bluuebunny/crossref_metadata_2025 huggingface dataset:
The fine structure of the secretory cells of the uterus (shell gland) of the chicken
Authors: Breen Philip C. , De Bruyn Peter P. H.
Published: February 2005

The secretory processes in the shell gland of laying chickens were the subject of this study. Three cell types contribute secretory material to the forming egg: ciliated and non‐ciliated columnar cells of the uterine surface epithelium, and cells of tubular glands in the mucosa. The ciliated cells as well as the non‐ciliated cells have microvilli, which undergo changes in form and extent during the secretory cycle. At the final stages of shell formation they resemble stereocilia. It is postulated that the microvilli of both cells are active in the production of the cuticle of the shell.

The ciliated cell which has both cilia and microvilli manufactures secretory granules which arise from the Golgi complex in varying amounts throughout the egg laying cycle. Granule production reaches its greatest intensity during the early stages of shell deposition. The ciliated cell probably supplies proteinaceous material to the matrix of the forming egg shell.

The non‐ciliated cell has only microvilli. Secretory granules, containing an acid mucopolysaccharide, arise from the Golgi complex. Some granules are extruded into the uterine lumen where they supply the egg shell with organic matrix. Others migrate towards the supranuclear zone. Here a number of them disintegrate. This is accompanied by the formation of a large membraneless space, which is termed “vacuoloid.” Subsequently the vacuoloid regresses and during regression an extensive rough endoplasmic reticulum with numerous polyribosomes of spiral configuration appears. It is suggested that material in the vacuoloid originating from the disintegrating granules is resynthesized and utilized for the formation of secretory product.

The uterine tubular gland cells have irregular, frondlike microvilli. During egg shell deposition, these microvilli form large blebs and are probably related to the elaboration of a watery, calcium‐containing fluid.
The biology of cartilage. I. Invertebrate cartilages: Limulus gill cartilage
Authors: Person Philip , Philpott Delbert E.
Published: February 2005

The endoskeletal structure supporting the gill‐books of Limulus polyphemus has been investigated by means of light and electron microscopy, chemical analysis and x‐ray diffraction. This tissue is a cartilage which has significant correspondences with both vertebrate cartilage and plant tissues. Morphologically, the Limulus cartilage resembles certain cellular vertebrate cartilages with relatively scant matrix, and also certain plant parenchyme, collenchyme and sclerenchyme tissues. Of particular interest, was the observation that during cytoplasmic division, a phragmasome‐like structure appears between the daughter cells of the dividing gill cartilage cells. This phragmasome‐like structure appears to be a precursor of new matrix (cell‐wall) formation between the young chondrocytes, in much the same fashion as its counterpart in plant tissues. Perichondrial cells and underlying chondrocytes contain lipid droplets, abundant glycogen and ribosomes, as do corresponding vertebrate cartilage cells. In some of the Limulus cells, glycogen and ribosomes appear to be admixed with lipid, forming aggregates in which all three materials are in intimate intraparticulate relationship. During molting, the number of ribosomes seen in chondrocytes increases. The tissue contains both hydroxyproline and hydroxylysine, and gives a weak x‐ray diffraction pattern.
Morphologic variation in the mandible of the white‐tailed deer (Odocoileus virginianus): A study of populational skeletal variation by principal component and canonical analyses
Authors: Rees John W.
Published: February 2005

A principal component analysis revealed that the two major components of mandibular shape variation among individuals within breeding groups of white‐tailed deer in Canada and the United States involve contrasts between the mandible and the dentition and between the premolars and the molars. Size variation appeared to account for 34% of the total variation within the groups, and the two major shape variations accounted for 23% and 8% respectively.

A canonical analysis was used to identify the major components of mandibular variation among the breeding groups and to provide measures of the proportion of the total variation accounted for by each component. Among male groups, size variation was associated with latitude, and the major shape variation was closely associated with longitude, so a bivariate plot of the first two canonical variates reflected the general geographic orientation of the populations.

The mandibular size in a Tennessee population that descended from Wisconsin and Michigan ancestors appears to have not decreased appreciably in the more southerly habitat after introduction more than 20 years ago. Changes in range conditions in eastern Upper Michigan over the past 30 years have not influenced local mandibular morphology as reflected by the first two canonical variates. Regardless of general smallness of individuals, the mandibular morphology of the deer from the Cross Timbers area in Kansas appears to approximate more closely that of northern populations than that of the more southerly populations from Oklahoma and Texas.

Sexual dimorphism on the first two canonical axes was observed.
Electron microscopy of cardiac tissue in a primitive vertebrate Myxine glutinosa
Authors: Leak Lee Virn
Published: February 2005

Hearts of the Atlantic hagfish, Myxine glutinosa were studied with the electron microscope after prefixation in phosphate buffered glutaraldehyde or buffered formalin and subsequent postifxation in phosphate buffered osmium tetroxide. Epicardial, myocardial and endocardial layers are identified; however the hearts of Myxine lack an extensive capillary system comparable to the coronary vessels of other vertebrate heart tissues. Instead, blood is supplied to cells via an elaborate system of channels which extend between numerous trabeculae that make up the cardiac wall of this organism. Fine structural features of special interest include the presence of numerous dense granules (chromaffin granules) within myofibers and also specific granular cells which lack the contractile elements that are characteristic of both skeletal and cardiac myofibers. Another prominent feature noted includes an elaborate system of tubular invaginations within the subjacent sarcoplasm. These elements appear to be specific for the myofibers. They are continuous with the plasma membrane and project into the peripheral sarcoplasmic matrix. Crystalline inclusions are also observed in the sarcoplasm of the myofibers. These are compared with similar inclusions in other cellular components. The Golgi complex is very extensive in the myofibers of Myxine, and granules of varying sizes and densities often appear in the vicinity of the Golgi saccules. The observations suggest that the numerous vesicles around the Golgi Complex represent intermediate stages in the formation of the chromaffin granules. The structure and function of the extensive tubular invaginations are compared with the transverse tubules reported in several mammalian heart tissues.
Ultrastructural and functional changes during metamorphosis of a proleg muscle and its innervation in Galleria mellonella (L.) (Lepidoptera: Pyralididae)
Authors: Randall Winnifred C. , Pipa Rudolph L.
Published: February 2005

Structural and functional changes have been correlated during metamorphic degeneration of a single muscle fiber, the plantar retractor of G. mellonella, its axon, and their junctions to determine which features persist as long as muscle contractility. Changes commence simultaneously in muscle and nerve near cuticular attachments, and spread towards the center. Alterations associated with the muscle, including appearance of collapsed tracheoles and mitochondria with dense bodies, begin late in the last larval instar. Within 12 hours after pupal ecdysis some tracheolar withdrawal occurs, sarcoplasmic reticulum becomes reduced, and many mitochondria have dense bodies, dense membranes, or are enlarged. By 17–19 hours primary myofilaments and striations begin to disappear, microtubules and autophagic vacuole‐like bodies appear, and phagocytes invade the muscle. It remains partially contractile upon electrically stimulating its nerve, the ventral nerve, until these changes spread throughout the fiber.

Neuromuscular junction changes, including appearance of dense mitochondria and isolation bodies, begin late in the last larval instar. Junctions become fewer, and none remain in those muscle areas where tracheoles, sarcoplasmic reticulum, and primary myofilaments have disappeared.

Preliminary studies on nerve discharge activity to the muscle suggest that nerve silence occurs at approximately the time when the muscle loses all contractility. In some axons isolation bodies appear and neurotubules are lost, other axons remain unchanged, and new ones develop later in the pupal state. Phagocytes invade the neural lamella and it disappears in the late pupa, but it reappears in the adult.

The adult ventral nerve has over three times more axons and a thinner layer of glial cells than the larval nerve.
Mechanics of respiration in the snapping turtle, Chelydra serpentina (Linné)
Authors: Gaunt Abbot S. , Gans Carl
Published: February 2005

The mechanism of lung ventilation in chelonians has been much debated. Electromyographic studies show that the basic mechanism in the snapping turtle, Chelydra serpentina, is dependent on the activities of four major respiratory muscles that are capable of varying the volume of the visceral cavity. The precise mechanism utilized varies in response to environmental factors, especially the depth to which the animal is submerged. Chelydra tends to reduce muscular activity to a minimum, and hydrostatic pressure or gravity replaces muscular effort whenever possible. The response is subject to hysteresis. Both the mechanics and pattern of ventilation in Chelydra differ from those of Testudo. The differences appear to be attributable in part to Chelydra's markedly reduced plastron and more extensive respiratory musculature and in part to the different habitats occupied by the two species.
Functional components versus mechanical units in descriptive morphology
Authors: Gans Carl
Published: February 2005

The concept of functional components was initially proposed by van der Klaauw ('45, '52) to indicate overlap of functional influences particularly in mammalian skulls; his analysis marked a departure from the study of single characters to that of function‐modified systems. A very similar set of terms is now coming into vogue to describe the mechanically separable components of highly kinetic fish, amphibian and reptilian skulls. In these cases the term functional unit often pertains only to the musculo‐skeletal system and is utilized during the process of description; it is often applied before a complete functional analysis has been carried out.

Yet, any structure tends to be affected by the influence of multiple functions, and any function will almost certainly affect multiple characteristics of the animal. Since functional components overlap, the term should not be used to label an essentially topographical dissection of the animal. It cannot be expected that each loosely connected component of a kinetic skull subserves as a single “function,” and that this function does not overlap onto other units.

It is suggested that the term mechanical unit be substituted as a label for the mechanical sub‐divisions often utilized to organize descriptions. The concept of functional units in the original sense then remains available as an analytical tool.
A comparative study of the adrenergic innervation of the iris and ciliary structures in 18 species in phylogenesis
Authors: Staflova Jaroslava
Published: February 2005

A detailed topography of adrenergic innervation in invertebrates (lobster), low vertebrates (fish, amphibians, reptiles, birds), and nine species of mammals is presented. Flack and Hillarp's specific fluorescent histochemical method using freeze‐dried material was used. Phylogenetically, adrenergic innervation appeared earlier under the ciliary epithelium and in the muscle than surrounding the vessels, and in all species many fibers were without any connection to the vessel walls. Adrenergic innervation was very rich in the dilator muscle extending toward the epithelium of the posterior chamber; a surprisingly rich network was found in the sphincter muscle and also in ciliary spaces of some species. Numerous fluorescent mast cells were visualized in the pecten of the bird eye and in the ciliary tissue of the sheep and cow.
Evidence for the fusion of myoblasts in amphibian embryos. I. Homoplastic transplantations of somitic material labeled with tritiated thymidine
Authors: Loeffler Clarence A.
Published: February 2005

In order to obtain more direct evidence for the occurrence of myoblast fusion in the developing amphibian embryo, the following transplantations were performed in vitro. The nuclei of early embryos. Ambystoma tigrinum and A. maculatum, were labeled with tritiated thymidine. Portions of prospective somite areas from these labeled donors were grafted homoplastically and orthotopically into unlabeled hosts of the same, or nearly the same, stage. The stages employed were: neurula, early tail bud, and late tail bud. Hosts were raised until they had developed into more advanced larval forms, fixed, sectioned, and prepared for radioautographic processing according to the customary procedures.

The histological preparations contained varying numbers of multinucleate myotubes of a “composite” nature: that is, individual myotubes contained labeled nuclei of the donor, side by side with unlabeled nuclei of the host. There was no doubt that the mononucleate myoblasts of the grafts had fused with those of the host species to form the mutlinucleate composite myotubes.

In addition to the above determinations, the method of thymidine labeling has proven to be a satisfactory method of tracing, in the context of the intact organism, somitic cell derivatives up to the feeding larval stage. Mesenchymal cells from the grafted labeled somitic tissues were consequently found in: dermatomic, sclerotomic and intermyotomic locations; the matrix of the dorsal fin; the limb bud; the abdominal muscles.
The ultrastructure of the cornea‐lens epidermis in the lateral eye of Limulus polyphemus
Authors: Whitehead Russell A. , Purple Richard L. , Hopper Kenneth
Published: February 2005

The structure of the “Corneagen,” i.e., the epidermis lying beneath the cornea‐lens of the lateral eyes of the adult intermolt Limulus polyphemus was studied with light and electron microscopy.

This layer is composed of heavily columnar cells containing a striking number of cytoplasmic microtubules. Many of the microtubules are grouped into compact bundles or fascicles, generally each cell having at least one microtubule bundle. The cornealens end of each cell has numerous microvilli, each with a core of delicate filaments. The crypts between microvilli end in extracellular expansions and plaques of electron dense amorphous material are associated with these terminal expansions. Cytoplasmic microtubules appear to insert into these dense areas.

The basal ends of the cells are thrown into many pseudopodial processes which extend into the surrounding extracellular space. The cytoplasm of the pseudopodia is composed largely of microtubules and their associated low density halos.

Junctional complexes consisting of zonulae adhaerens and septate desmosomes are present between adjacent cells. Mitochondria, ER, cytoplasmic vesicles, Golgi stacks and other ultrastructural details of the epidermal cells are described. The ultrastructure of a column of pigment free processes lying between the apex of the lens cone and the underlying photoreceptive portion of the ommatidium is also described. Ducts or vessels of uncertain origin are present in the inter‐ommatidial spaces.

Possible roles played by the microtubules, the significance of their disposition and of their association with the dense subsurface plaques are discussed in terms of intracellular support, epidermis‐lens attachment and extracellular pattern determination. In addition, the likelihood of the dense plaques being the site of microtubule assembly is considered.
A comparative study of the ring glands from wild type and 1(2)gl mutant Drosophila melanogaster
Authors: Aggarwal Surinder K. , King Robert C.
Published: February 2005

Drosophila melanogaster homozygous for the second chromosomal, recessive lethal gene 1(2)gl form puparia much later than wild type (+) and are unable to metamorphose. Implantation of + ring glands accelerates puparium formation by 1(2)gl hosts. The ring gland is a compound structure containing the prothoracic glands (pg), corpus allatum (ca), and corpus cardiacum (cc). An electron microscopic study demonstrates that in both the pg and ca the most common subcellular component is smooth surfaced endoplasmic reticulum (ser). In + flies the amount of ser per pg increases by ten times during the four hour prepupal period. In 1(2)gl flies which have spent two days in the prepupal period the pg looks juvenile and contains only 1% the amount of ser per cell found in the + prepupal pg. The ca cells look alike in both + and 1(2)gl individuals, and the cortical cells of the cc in both contain abundant neurosecretory spheres. We suggest that the + allele of 1(2)gl indirectly influences the synthesis of ser by the pg and that this is the site where dietary cholesterol is transformed to ecdysone.
Genesis of the reproductive system of mosquitoes. I. Female of Aedes stimulans (Walker)
Authors: Ronquillo Maria C. , Horsfall William R.
Published: February 2005

The feminine dimorph has unique structures that produce eggs, select salubrious sites for the offspring, store sperm, and void the eggs. This paper provides a time table for development of these parts in Aedes stimulans based on preparations examined at 5‐hour intervals when reared at 21°C. All growths of imaginal parts proceeds independent of activities in the larval tissues.

Ovaries produce the eggs in terminal follicles of the ovarioles. Besides ovarioles each ovary contains sheaths for the ovarioles, pedicels attaching them to a central canal, the calyx, ovarian sheath and muscles. Ovaries are recognizable in newly hatched larvae as caps of cells on larger masses which become part of the delivery system for eggs. Each ovary grows forward from its attachment first as a column of cells that differentiates into the several tissues by the time the insect enters pupal life. Prior accounts have considered the ovary as the whole mass of cells on each side of the hemocoel of segment 6. Only the most anterior cells recognizably distinct at the end of embryogeny are generative.

The delivery system for eggs is composed of the lateral oviducts and median or common oviduct. Primordia from which the former are derived are present from the end of embryogeny and throughout larval life as two distinct parts. Two ovoid masses occur in the hemocoel of segment 6. To each of these is attached a filament extending backward to an attachment ventrally and caudally in segment 7. They are rapidly changed into definitive lateral oviducts late in pupal life. The single primordium for generating the median genital tract appears during instar 3 as a caudal ventral plate of cells in segment 8 between a pair of bilateral buds and invaginates during instar 4 to form (1) the common oviduct from a midventral pouch, (2) three spermathecae from two lateral invaginations and (3) the elaborate vaginal area. The bilateral buds form no parts of the female.

The post‐vaginal area or atrium with its accessory organs is derived in part from the ventral plate of segment 8 and that of segment 9. The imaginal disc in segment 9 is present at the end of embryogeny as primordial buds and ventral plate and development is delayed until early pupal life when it projects inward to form part of the atrium and pouches once to form the common opening for the duct of the accessory gland and the canal to the bursa copulatrix. The buds of this disc produce no feminine parts.

During the second larval instar lateral primordia appear as a pair of shields in the anal segment. They develop slowly until pupation when they extend caudally as two flaps called “cerci” in culicid literature and this paper.
Differentiation and degeneration in the motor horn of the foetal mouse
Authors: Flanagan Ann Elizabeth Harris
Published: February 2005

The development of the motor horn of the foetal mouse was investigated. A sampling technique was evolved using cresyl violet stained material.

A decline in the number of motor neuroblasts occurred during the development, on each side, of four definitive motor regions from a single longitudinal column. The total number of motor horn cells fell from about 100,000 on the eleventh day after mating to about 25,000 on the fourteenth day. The early stages of this decline (between 11 and 12 days) are probably explained by the fact that not all neuroblasts in the region differentiate into motor cells; he later decrease can be entirely accounted for by the number of degenerations.

Irradiation of the foetal mouse with a dose of 50 rads of cobalt‐60 gamma‐radiation resulted in an excess of about 20,000 differentiating motor cells on the thirteenth and fourteenth days. Irradiation increased the actual number, but not the percentage, of degenerations. This suggests that differentiation is a phase in the growth process which proceeds degeneation.
The hatching thread of praying mantids: An unusual chintinous structure
Authors: Kenchington W.
Published: February 2005

The hatching threads of praying mantis embryos are silk‐like in appearance, but cellular in origin. Their development can be divided into four phases. In phase 1 each embryonic cercus produces a hollow column of cells which is pushed out dorso‐laterally, on either side of the embryo, between the epidermis and the chorion. In phase 2 each column becomes transformed into an unbroken helical cellular filament. The terminal five or six cells at the distal end of each filament become permanently attached to the inner surface of the chorion. The cellular arrangement of the filament is superseded by an apparent syncytial condition. In phase 3 the extensive proximal parts of the two filaments become folded into a compact space, flanked by the cerci and styli, at the tip of the abdomen. Throughout phase 4 the filaments remain in two tightly coiled groups, connected to the chorionic attachments by loosely coiled distal regions. Progressive secretion of chitin by, and around, each filament forms a sheath, 1–2 μ thick, which provides the tensile component of the hatching threads. During emergence these threads become unravelled to form a double thread which allows the insect to hang from the ootheca and complete its first ecdysis.
Studies on the nature and localization of acid phosphatase in normal and lens‐regenerating urodele eyes. II. Biochemical assay
Authors: Miller Neil R. , Rafferty Nancy S.
Published: February 2005

Biochemical assay of acid phosphatase in normal and lens‐regenerating eyes of the urodele Diemictylus viridescens, using p‐nitrophenyl phosphate as substrate, demonstrates both soluble and lysosomal fractions of the enzyme. While the specific activity of the soluble fraction remains unchanged during lens regeneration, the lysosomal fraction shows four distinct rises in specific activity during the thirty‐day regeneration period studied. These peak activities on the second, eighth, fifteenth, and twenty‐second days post‐lentectomy apparently correspond to lysosomal activity in the processes of wound healing, iris depigmentation, and lens differentiation which occur during urodele lens regeneration. On the basis of biochemical and histochemical studies as well as observations of morphological changes in the urodele eye as lens regeneration proceeds, it is postulated that there is a significant correlation between these morphological changes and the level and localization of the lysosomal acid hydrolases in the tissues in which the changes occur.
A comparative study of the embryological development of the median cord in hemiptera
Authors: Springer Charles Anthony , Rutschky Charles W.
Published: February 2005

Median cord development is uniform in six families of Hemiptera and five non‐hemipterans. The median cord arises independently from the lateral cords and is histologically distinguishable from the latter throughout development. Intrasegmentally, median cord nuclei possess prominent nucleoli and many small chromatin granules surrounded by clear nuclear sap. This region forms what appear to be glial elements at the midline of the neuropile. Intersegmentally, a spherical clump of eight to twelve large nuclei develops surrounded by dark‐staining granular cytoplasm. Each intersegmental clump migrates anteriorly into the preceding ganglionic region but degenerates soon after katatrepsis.
Morphology of the trunk of Corynosoma hamanni (acanthocephala: Polymorphidae)
Authors: Holloway Harry L. , Nickol Brent B.
Published: February 2005

Morphological study of Corynosoma hamanni (Linstow, 1892) was continued with the intention of presenting a morphological description of a single, well defined species.

Sexual dimorphism is exhibited in body size, males being larger, and in body spination. Trunk spines are arranged in a pattern similar to that of Corynosoma semerme and do not extend onto the bursa as reported in the original description of C. hamanni.

Two testes, located side by side, are followed by six cement glands arranged in two groups of three glands each. One group is behind each testis. Cement ducts from glands on the right side cross over Saefftigen's pouch and join to form a reservoir on the left side; ducts from cement glands on the left side fuse forming a second reservoir. The two cement reservoirs unite before emptying into the ejaculatory duct. The bursa possesses rays on its outer wall and numerous, well‐developed papillae in the muscular cap.

In females, a ruptured genital ligament sac is attached partially on the dorsal wall of the uterine bell and partially on a column of six cells projecting from the bell's base into its lumen. Postericrly the dorsal wall of the bell has two protruding pockets behind which occur ten cells composing the selector apparatus. Dorsal openings into the pseudocoelom occur on either side of the uterine bell. Two muscular tubes conduct eggs into the uterus. Female C. hamanni frequently form genital vestibules in which the genital pore occurs along the dorsal wall and not, as reported for some species, at the anterior tip.

Eggs of C. hamanni possess four membranes rather than the previously reported three.
Seasonal changes in testicular histology of three species of the lizard genus Uma
Authors: Mayhew Wilbur W. , Wright Shirley J.
Published: February 2005

Desert‐dwelling male Uma notata, U. inornata and U. scoparia were autopsied monthly from 1959 through 1962. Seasonal changes in the histological morphology of the testes were observed. A series of eight stages, indicating these changes in spermatogenic activity, was established. These categories arbitrarily divide a continuous process into several recognizable stages.

Present evidence indicates that male breeding cycles can be determined rather precisely by examining any of several reproductive features. Data from several sources reveal that the male breeding season of U. scoparia is shorter than that of U. notata or U. inornata. Nevertheless, the testes of all three species appear to function reproductively during the hottest month of the year. Possible explanations for this ability are suggested.

Little difference was observed in the time the seminiferous tubules of U. notata testes reached full breeding condition (stage 6) following dry winters. This is in contrast to the time motile sperm appeared at the cloacal end of the vas deferens in these animals. Thus is appears that the major cause of postponement in male U. notata reproductive activity following dry winters is due to a delay in sperm reaching the vas deferens rather than a retardation in sperm production.
The spleen of the cowbird
Authors: Ewart David F. , McMillan Donald B.
Published: February 2005

A histological study of the spleen of the Brown‐headed cowbird, Molothrus ater, is presented.

One of the most striking differences from the mammalian spleen is the lack of trabeculae and of smooth muscle in the capsule which would suggest that the spleen is not an organ of storage or pumping of blood. Without trabeculae to foster the close association of the major arteries and veins, these vessels take separate courses. Their support is provided by elaboration of the collagenous and reticular fibres of the stroma.

A peculiar ovoid structure, the ampulla, carries the blood from the terminal arterioles of the white pulp to both the sinusoids and the reticular cords of the red pulp so that both open and closed circulations are seen but the open circulation predominates. The ampulla has perforated walls consisting of a simple cuboidal endothelium surrounded by a dense reticular sleeve. Leucocytes were seen passing through the holes in the walls of the ampullae by diapedesis. It is suggested that the ampullae may be contractile and act as sphincters controlling the flow of blood through the spleen.

The major functions of the spleen appear to be haemopoiesis, production of antibodies, and filtration of blood.
Ultrastructure of human labial salivary glands. III. Myoepithelium and ducts
Authors: Tandler Bernard , Denning Carolyn R. , Mandel Irwin D. , Kutscher Austin H.
Published: February 2005

Myoepithelial cells were present between the basal lamina and the acinar secretory cells of human labial salivary glands. In form and disposition, they resembled myoepithelial cells in the major salivary glands. Many of these cells possessed single cilia on their upper surfaces. Such cilia occasionally extended into invaginations of the overlying secretory cell.

The intercalated ducts were variable in occurrence. Their epithelium ranged from columnar to squamous, and showed few signs of secretory activity.

Few intralobular ducts possessed basal striations. While mitochondria were abundant in non‐striated cells, they were randomly disposed in both basal and apical cytoplasm, and the basal plasmalemma showed only occasional infoldings. The paucity of true striated ducts in labial salivary glands may be responsible for the high concentration of sodium and chloride in unstimulated labial gland salivary secretions.
Histomorphic changes following chronic adrenocortical activation and inhibition in the pigeon
Authors: Bhattacharyya Tapan K. , Ghosh Asok
Published: February 2005

Gravimetric and histologic modifications in the pigeon were studied following chronic therapy with ACTH and metopirone (SU 4885) for a period of 15 days. The organs studied were proventriculus, duodenum, heart, kidney, salivary gland, pancreas, liver, uropygial gland, thymus, spleen, bursa fabricii, testis, ovary, islets of Langerhans, adenohypophysis, thyroid and interrenal and chromaffin tissue of the adrenal gland. Induced states of hyper‐ and hypoadrenocorticalism elicited pathomorphic changes in endocrine and reproductive systems and some other organs of the pigeon. There were many differences and similarities in the nature of response of some organs following the two experimental conditions. Many of these cellular interactions might have resulted from alteration of interrenal function in the pigeon.
Haemocytes in the repair of wounds in an insect (Rhodnius prolixus)
Authors: Lai‐Fook Joan
Published: February 2005

Four types of haemocytes may be distinguished in Rhodnius adults, based on their fine structure. The plasmatocytes are most active in the repair of an integumental wound. They contain dens homogeneous granules whose contents become less dense in response to wounding until microtubules about 150å in diameter are distinguishable. The significance of these changes is not yet known. Tight and intermediate junctions, and septate desmosomes appear between haemocytes which have accumulated in an excision.
The fine structure of the trout blastoderm,Salvelinus fontinalis(Mitchill)
Authors: Dickson D. H. , Battle Helen I.
Published: February 2005

The Speckled Trout blastoderm at the late high blastula stage is characterized by two different cell populations. The “light” blastomeres comprise one cell type while the “dark” and “medium” blastomeres appear to differ from one another only in degree and thus may be considered as the second type.

“Dark” and “medium” blastomeres are irregular in shape, are located centrally and deep in the blastoderm, have an abundance of smooth endoplasmic reticulum with associated 520 Å glycogen particles and a single mitochondrial profile. The “light” blastomeres have randomly arranged glycogen particles in minimal quantities in contrast to the “medium” and “dark” blastomeres and in addition exhibit three mitochondrial profiles, which could however represent artifacts.

It is postulated that in the Speckled Trout cellular differentiation has commenced by the third day of incubation at 10°C and that this is manifested visually by the appearance of two different cell populations; the more differentiated “dark” and “medium” blastomeres possibly destined to give rise to the hypoblast and the less differentiated “light” blastomeres.
Histology of the alimentary canal during the metamorphosis of Hyalophora cecropia (L.)
Authors: Judy Kenneth J. , Gilbert Lawrence I.
Published: February 2005

The histology of the alimentary canal is described for the last instar larva, pupa, and adult Hyalophora cecropia (L.). Particular attention is given to the changes occurring in the midgut during the larval‐pupal transformation and in the hindgut during the pupal‐adult transformation. Descriptions are made as to the nature of the imaginal rings at each end of the midgut and a new structure is described in the larval ileum. The formation of adult rectal pads is followed in detail.
Cyclic changes in the testis of the brook stickleback Eucalia inconstans (Kirtland)
Authors: Ruby Sylvia M. , McMillan Donald B.
Published: February 2005

The cyclic changes in the testis of the five‐spined stickleback Eucalia inconstans (Kirtland) were studied histologically. Specimens were trapped between July 1965 and July 1967 in a shallow pond near London, Ontario.

A three‐dimensional microscopic study showed a main vas deferens and a system of primary, secondary and tertiary tubules.

The testis cycle was divided into seven arbitrary stages. Spawning takes place from mid‐April to mid‐July. This is followed by the division of primary spermatogonia which are located along the walls of the tubules, producing cysts of spermatogonia enclosed in connective tissue which is surrounded by a thin epithelium. Both primary and secondary spermatocytes develop within these cysts. Breakdown of the cysts occurs with the development of spermatids and spermiogenesis occurs while spermatids are free in the tubules. Over‐wintering of mature sperm takes place. Development of mature sperm from primary spermatogonia takes about 156 days.

Germinal epithelium is absent but primary germ cells are believed to be those cells occupying the spaces between the tubules of the testis. No tissue which might be implicated in hormone production was observed.

Phagocytic invasion of the testis has been studied. Massive infiltration by phagocytes is believed to be responsible for the sudden increase in testis weight observed during spawning. These cells ingest sperm nuclei and groups of them have been observed in the lumen of the tubules and the vas deferens, probably on their way out of the body.
An ultrastructural study of the submandibular glands of the squirrel monkey, Saimiri sciureus
Authors: Cowley Linda H. , Shackleford John M.
Published: February 2005

In squirrel monkey (Saimiri sciureus) the position of submandibular glands in the neck, on either side of the trachea, more closely resembles that of rodents than that of other primates. The glands exhibit seromucous acini and mucous tubules with seromucous demilunes. Electron microscopy shows basal cytoplasmic folds and well‐developed intercellular tissue spaces and canaliculi only in relation to seromucous cells. Greatly dilated cisternae of the granular endoplasmic reticulum and prominent Golgi membranes are characteristic of the mucous cells. The secretory granules of seromucous and mucous cells are morphologically distinct and indicate chemically different products for the two cell types. Histochemically, the seromucous cell shows the presence of acid mucosubstance as indicated by the PAS and Alcian blue techniques. Preliminary studies showed no appreciable quantity of amylase in submandibular glands. The intercalated duct cell is juxtaposed with the acinar cell or mucous tubule cell. Short luminal microvilli, prominent Golgi complexes and scant apical granules are notable features of intercalated duct cells. Four cell types compose the striated ducts, viz., granular light cells, agranular dark cells, vesiculated dark cells, and basal cells. Peripheral nerves are found in five different locations: in the connective tissue (interstitial), between adjacent myoepithelial and mucous‐secreting cells, in the intercellular space between adjacent secretory cells, and between basal plications of striated ducts and between adjacent myoepithelial and intercalated duct cells.
The effects of essential fatty acid deficiency on the fine structure of mouse skin
Authors: Menton David N.
Published: February 2005

Mice raised from weaning on a diet free of essential fatty acids (EFA) develop a greatly thickened epidermis and stratum corneum with a concomitant increase in transepidermal water loss. The hyperplastic epidermis of EFA deficient mice is characterized by widely separated columnar cells in the stratum basale, an abundance of keratinosomes at the periphery of the cells in the stratum spinosum, and an unusually well‐developed stratum granulosum in which many keratinosomes are fused with the plasma membranes. Many vacuoles, lacking a membrane, are observed in the stratum granulosum and stratum corneum; these presumably correspond to histochemically demonstrable droplets of phospholipid. The horny cells in the stratum corneum of deficient mice also contain many membrane bound vesicles many of which can be identified as mitochondria. The most striking change in the horny cells, however, is the wide separation of epidermal filaments which may allow free diffusion of bulk water through the stratum corneum. The low rate of transepidermal water loss in normal skin may result in part from the ability of the stratum corneum to bind water in the small intersticies between the keratin filaments. The EFA, i.e., arachidonic acid, may serve to bind phospholipids to the structural protein of filaments and membranes thus binding water at these protein‐lipid interfaces.
An electron microscopic study of the spermathecal complex of virgin aedes Aegypti mosquitoes
Authors: Jones Jack Colvard , Fischman D. A.
Published: February 2005

Virgin mosquitoes were studied with the electron microscope. Spermathecal duct walls contain cuticle, epithelium, and a richly innervated spiral muscle; myocytes are linked by desmosome‐like attachment plaques to the underlying epithelium. Periductal cells along upper portions of the ducts have a large secretory droplet within a highly irregular extracellular lacuna and are attached to a long secretory ductule through which finely granular material is delivered to the duct lumen and this enters the spermathecae. Basal gland cells of spermathecae have short ductules containing secretion in virgins. Secretory material in spermathecae of virgins does not form a complete internal membrane.
Comparative morphology, homologies, and functions of the male system in oribatid mites (Arachnida: Acari)
Authors: Woodring J. P.
Published: February 2005

The penis is basically a double‐walled oval cone. The weak type penis (only 2 species) has a weak tongue, lacks a bridge, and is elongate. The strong type (all others) has a bridge, a strong tongue, thicker walls, and is short. An accessory gland and a common vas deferens always open into the inner cup lumen (= ejaculatory duct). The massive tongue muscles may open the penal orifice. A pair of penal retractor muscles originate on the body wall. Penal protrusion and perhaps partial extrusion of stalk substance is by hemolymph pressure. The penis is completely homologous to the ovipositor. The genital discs are cuticular cups containing glandular tissue and are retractible by muscles originating on the body wall. The minute, rod‐like, immobile sperm are mixed with seminal fluid and stalk material secreted by seminal vesicle cells. This mixture is carried via the vase deferentia by peristalsis to the penis. Semen and stalk substance (protein) are somehow separated in the ejaculatory duct into separate pools, with stalk substance nearest the penal orifice. Upon penal protrusion, a bit of stalk material is extruded and fastened to the ground, and upon raising of the mite's body the stalk is “drawn out.” Finally, the ball of semen, adhering to the stalk tip, is pulled through the penal orifice.
Cell proliferation in vivo and in vitro in visceral organs of the adult newt, Triturus cristatus carnifex
Authors: Monnickendam Marjorie A. , Millar John L. , Balls Michael
Published: February 2005

The mitotic and labelling incidence of intestine, liver, spleen and pancreas cells of Triturus cristatus carnifex adults kept at 15°C, 20°C, 25°C and 30°C were examined. Intestine mitotic and labelling incidences were highest at 25°C and lowest at 30°C. There was no significant difference between 15°C and 20°C. No such relationship could be shown for liver, spleen or pancreas, which had very much lower mitotic and labelling incidences. In culture, intestine mitotic and labelling incidences fell significantly within the first four hours, and maintained these low levels for the next five days. In contrast, liver mitotic and labelling incidences rose for 9–11 days, and then began to fall, while pancreas mitotic and labelling incidences reached peak values at day 5, and were kept in good condition for up to 14 days.
A possible neuroendocrine system in polynoid polychaetes
Authors: Baskin Denis G.
Published: February 2005

Within the supraesophageal ganglion of polynoids is a vertical fiber tract which has the appearance of a “Y” in transverse sections of the brain, and contains the axons of many neurosecretory cells. The granule‐filled terminals of these neurosecretory fibers are found at the base of the tract where they are in contact with the inner surface of the sheath covering the ventral surface of the brain. This sheath separates these neurosecretory endings from an underlying pericapsular epithelium which is thicker in this region. Beneath this pericapsular epithelium is a coelomic sinus. The dorsal blood vessel is located within this sinus and is “innervated” by a pair of fiber bundles that pass out of the brain at the base of the vertical fiber tract. The outer surface of the vessel is covered by epithelioid cells which contact these fiber bundles and the thickened pericapsular epithelium, and sometimes contain granular cytoplasmic inclusions. The lumen of the vessel is continuous with the lumina of a pair of cellular, thickwalled structures of unknown function which are attached to the ventro‐lateral margins of the brain. The relationship between neurosecretory endings, enlarged pericapsular cells, coelomic sinus and blood vessel provides morphological evidence for the hypothesis that these structures are elements of a neuroendocrine system, similar in some respects to the brain‐infracerebral gland complex of nereid and nephtyid polychaetes.
The prenatal morphogenesis of the lateral nasal wall in the rat (Mus rattus)
Authors: Vidić Branislav
Published: February 2005

In the course of this investigation 24 fetuses of the Sprague‐Dawley rats were used. Pregnant animals were sacrificed at 12, 14, 16, 18, and 20 days of gestation. The fetuses were removed and fixed in buffered formalin solution. The heads were dehydrated, embedded in paraffin, and the nasal cavities were sectioned serially. Light microscope observations were made on 10 to 15 μ thick sections stained with H and E, Mallory's trichrome stain, and Gomori's alkaline phosphatase stain. The 12 day old fetus possessed well developed olfactory depression with a thick epithelial covering. The olfactory fossa was still separated from the buccal cavity by a solid layer of young mesenchyme. In the 14 day old fetus the communication between the nasal and buccal cavities was established. The palatal shelves developed still vertically. All the turbinates and the nasal capsule were already differentiated. The glandular system was represented with the main and two to three accessory excretory ducts. During the sixteenth day of prenatal development, the sinus and the sinus related glands became for the first time evident. The ossification of the membranous parts of the lateral nasal wall was initiated. In the next two developing stages the maturation of the cartilage, the increasing ossification in the membrane, and the further differentiation of the glands were the major morphological changes in the formation of the lateral nasal wall.
Ultrastructure of the excretory tubes of the mite Macrocheles muscaedomesticae (Mesostigmata, Macrochelidae) with notes on altered mitochondria
Authors: Coons Lewis B. , Axtell Richard C.
Published: February 2005

The fine structure of the excretory tubes of the mesostigmatid mite Macrocheles muscaedomesticae were investigated. These paired tubes are partially ensheathed by fat body and invested throughout by a branching system of visceral muscles. The fine structure of the cells of the excretory tube is in general similar with only minor differences found throughout its length. The basal region of each epithelial cell of the excretory tube borders the hemocoel and is divided into many compartments by the extensive infolding of the plasma membrane. Mitochondria and vacuolar inclusions are often closely associated with these compartments. More than one morphological type of mitochondria was found distributed throughout the cells of the excretory tubes. The most commonly encountered type had well developed cristae and an electron dense matrix. Less commonly, mitochondria with somewhat poorly developed cristae and a translucent matrix often containing myelin‐like figures of varying complexity were observed. It is suggested that they represent part of a normal process of mitochondrial degeneration. The apical region of the cell has a border composed of plate‐like folds of the plasma membrane termed microlamellae. The lumen contains abundant granules of the excretory product.
Genesis of the reproductive system of mosquitoes. III. Supernumerary male genitalia
Authors: Voorhees Frank Ray , Horsfall William R.
Published: February 2005

The origin of supernumerary gonapophyses in a polymorphic variant of Aedes stimulans has been determined histologically. Genotypic males (Mm) will develop gonapophyses on abdominal segment 8 when primordia on the larvae are subjected to a high‐to‐low thermal regimen. The gonapophyses develop from the normally evanescent podal buds of the eighth imaginal disc. Their course of development is similar to that of the normal gonapophyses that arise from the podal buds of the ninth imaginal disc.