bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcium uptake in glycerol‐extracted rabbit psoas muscle fibers. I. Biochemical properties and conditions for uptake
Authors: Elison C. , Fairhurst A. S. , Howell J. N. , Jenden D. J.
Published: February 2005

Rabbit psoas muscle fibers, extracted in 50% (w/v) glycerol for 20 hours, concentrate up to 300 μmol calcium per gm protein when placed in a suitable electrolyte environment at pH 6.5 containing ATP and 47Ca in the form of a Ca/EGTA metal buffer system. This property is retained at [Ca++] down to 2 × 10−8 M, the lowest studied. The kinetics of Ca pickup are consistent with a mathematical model based on diffusion of Ca as the rate‐limiting factor. The pickup is dependent upon ATP and is increased by inclusion of CP or PEP. It is promoted by oxalate, fluoride, phosphate and pyrophosphate, which share the property of forming relatively insoluble calcium salts. Ability to concentrate calcium disappears on prolonged extraction in glycerol and after preincubation with desoxycholate.

These properties are similar to those previously described for a granular fraction of muscle homogenates, and it is concluded that both are probably attributable to functional remnants of sarcoplasmic reticulum.
Studies on the transport of carbohydrate in Crithidia luciliae
Authors: Min Hong S.
Published: February 2005

The entrance of carbohydrates into the cells of C. luciliae has been studied, using the non‐utilizable monosaccharides: L‐sorbose, D‐xylose, L‐xylose, D‐arabinose, L‐arabinose, L‐rhamnose, D‐lyxose, D‐2‐deoxyglucose, and L‐fucose; all nine sugars entered the cell. At 0.5 mM external concentration the rate of increase in intracellular concentration is constant for all sugars until the intracellular concentrations equal or exceed the extracellular concentration. At 20 mM external concentration, the rate of increase of intracellular concentration decreases continuously and the maximum intracellular concentration never exceeds the extracellular concentration. There is competition between monosaccharides presented simultaneously to the cells and the transport mechanism shows enormously greater affinity for glucose than for other monosaccharides. The rate of carbohydrate entrance is inhibited 50% and 70% by KCN(10−4 M) and DNP(10−5 M) respectively at 0.5 mM external concentrations. However, these inhibitors do not affect transport from external concentrations of the order of 0.02 M. These data are interpreted as indicating two mechanisms for carbohydrate entrance: (a) an active transport mechanism, active at low external concentration and dependent upon a supply of metabolic energy; (b) facilitated diffusion, of importance only at high external concentrations. These results are compared with those reported in the literature for other types of cells.
Absorption of fat in the alimentary canal of Tilapia mossambica (Peters) (Teleostei)
Authors: Sivadas P.
Published: February 2005

Studies on the absorption of fat in Tilapia mossambica point out the existence of a differential absorptive behavior in the different limbs of intestine. It appears that the relative increase in fat absorption in the anterior limb of the intestine is dependent on its functional status. It has also been pointed out that the sudanophilic lipid in its particulate form is transferred from the lumen of the intestine to the absorptive cell through the spindle shaped canals.
Limiting factors involved in CO2 production by starved and X‐irradiated starved yeast cells
Authors: Spoerl Edward , Doyle R. J. , Thompson M. E.
Published: February 2005

Studies of reduced CO2 production by starved yeast cells were carried out to localize the site limiting this process and responsible for a greater production by irradiated cells. Cell‐free extracts prepared before and after starvation of cells, and from irradiated and unirradiated cells, showed similar hexokinase activity and produced similar amounts of CO2. These results demonstrated that rate limiting glycolytic enzymes did not decay during starvation, were not induced during a lag period in CO2 production which could be overcome by glucose incubation, and were not responsible for differences in CO2 production between irradiated and unirradiated cells. Possible limiting factors involved in these differences include glucose transport as a consequence of differential decay during starvation, restricted cofactor synthesis and an enzymic binding or compartmentalization.
Pressure‐temperature effects on the form‐stability and movements of Euglena gracilis var. Z.
Authors: Byrne John , Marsland Douglas
Published: February 2005

The phytoflagellate, Euglena gracilis var Z, maintained in a chemically defined culture medium, was subjected to various high hydrostatic pressures (10,000–15,000 psi) at various temperatures (15° 20° and 25°C). The effects on form stability, locomotion, euglenoid movement and flagellatory activity were observed at various times after the application of pressure.

The pressure‐temperature relations of form stability clearly show that the supporting gel structures of the cell, presumably the peripheral gelated cytoplasm and the pellicle, may be identified as Type II systems in the Freundlich classification, since they undergo solational weakening with increasing pressure and with decreasing temperature. The gelational state of these structures appears to be unusually high, however, since at each given temperature, an usually high intensity of pressure is required to produce an observable loss of stability, i.e. a rounding up of the normally elongate cells.

Flagellatory movement continued even at the highest pressure, but locomotion was abolished in all rounded and partly rounded individuals. Euglenoid movement ceased at relatively lower pressure (about 10,000 psi).

The rounding of the euglena, even at maximum pressures, was not accompanied by any cytolysis. In this respect, euglena resembles amoeba and other sarcodinans, rather than paramecium and other ciliates.

Euglena exhibited a rapid transient post‐pressure contraction, similar to that which has been described in several other protistan forms. No irreversible changes were observed. Normal form and activity reappeared in almost all specimens within about five minutes, subsequent to decompression.
Red Cell and plasma sodium and potassium changes in the San Diego pocket mouse during hibernation
Authors: Andrus William DeW. , Starr Stuart E. , Strathmann Richard R.
Published: February 2005

As compared to that of active animals, blood from P. fallax torpid at an ambient temperature (TA) of 15°C (hibernation) shows a decrease in red cell K and increases in cell Na and plasma K, and analyses of blood from animals hypothermic at TA = 25°C (aestivation) suggest increases in cell Na and plasma K. Blood electrolyte metabolism of this hibernating rodent shows no special resistance to hypothermia.
The influence of rat and frog liver enzymes on the hydrolysis of ortho and pyrophosphoric esters of thiamine
Authors: Singer‐Altbeker Rina , Ber Artur
Published: February 2005

Homogenates of rat and frog liver were incubated with ThDP and ThMP at different pHs.

The products of hydrolysis were identified by paper chromatography.

In experiments carried out at pH 9 with ThDP as substrate in the presence of rat liver, the spot corresponding to Th did not appear on the chromatogram. This was in contrast with parallel experiments with frog liver. ThMP from commercial source behaved differently toward enzymatic decomposition than ThMP originating from hydrolysis of ThDP. Attempts have been made to explain these differences.
The mechanism of calcium and magnesium uptake from sea water by a marine bacterium
Authors: Carroll J. J. , Greenfield L. J. , Johnson R. F.
Published: February 2005

Previously, the precipitation of calcium carbonate by marine bacteria had been described in which bacteria occupy the nucleus of micro‐aragonite crystals. The mechanism of the process of calcium‐binding by the cells is the subject of this study.

Sea‐water cultures of Pseudomonas piscicida (Bein) Buck et al. (A.T.C.C. 15057) were grown under standardized conditions (1% peptone‐artificial sea water, 25°C). Cells of various ages were collected and analyzed for calcium and magnesium content under various conditions. Material composing cell walls was fractionated and analyzed for low molecular weight components.

Cells up to a week old (1% peptone‐artificial sea water) increase their content of calcium from 0 to 55% of the dry weight. Furthermore the Ca/Mg ratio in young, actively growing cells (up to 24 hours old) is one‐fifth (approximately that of sea water). By 72 hours, the ratio is 1/2.5. At one week, it is 1/1, and by two weeks calcium content exceeds that of magnesium.

Concentration of the alkaline‐earth elements is primarily by the cell envelope, particularly by the muco‐polysaccharide fraction. This fraction constitutes 20–25% of the dry weight of cells during rapid growth but increases to 47–52% of dry weight after one week. Binding of alkaline earths to active sites of muco‐polysaccharide is probably by hydrogen bonds and London interaction forces, as removal of the elements by washing is readily accomplished. In addition, a ready source of calciumactive ligands is available in the ammonia produced in quantity by the bacteria. The complex formation by ammonia and Ca, coupled with the increase in pH, favors binding of calcium over that of magnesium by the cells.
Studies on synchronously dividing cultures of Euglena gracilis Klebs (strain Z). I. Attainment and characterization of rhythmic cell division
Authors: Edmunds Leland N.
Published: February 2005

Euglena gracilis Klebs (strain Z) was grown synchronously on an aerated, inorganic salt medium at 25°C under a LD: 16, 8 or LD: 14, 10 light‐dark cycle (light intensity of 3,500 lux). In either cycle balanced growth occurred with a doubling of cell number every 24 hr. until limiting conditions of light intensity were reached, due to mutual shading, at about 1.0 – 1.5 × 105 cells/ml. An increase of light intensity to 7,000 lux permitted balanced growth to occur to higher cell concentrations, but with no significant change in generation time. With both photofractions, the fission burst during any given cycle began 13–14 hr after the onset of the light period and continued for about 9–11 hour. Synchrony was slightly greater in the LD: 14, 10 cycle with division confined almost entirely to the dark period; this regime was later adopted for metabolic studies. Synchronous cell division was lost in continuous bright light (3,500 or 7,000 lux), continuous darkness, and in some continuous dim light regimes. The addition of certain organic substrates to the medium resulted in a breakdown of synchrony also, and logarithmic growth ensued. The generation time of cells in either continuous bright light, or with ethanol (0.006 M) and a LD cycle was 11–12 hr.
Destruction of mouse and rat embryo cells in tissue culture by lymph node cells from unsensitized rats
Authors: Ginsburg Haim , Sachs Leo
Published: February 2005

A specific destruction of embryo monolayers was obtained in tissue culture, by growing suspensions of lymph node cells from unsensitized adult random bred rats, on mouse and on randomly bred rat monolayers. Mouse monolayers were lysed partially or completely in all the experiments. When two different batches of rat monolayers were used, the first batch was destroyed in three out of six experiments and the second in one out of five. The earliest destructive effect with unsensitized cells was observed on the sixth day. Destruction of monolayers followed the appearance of large numbers of large lymphoid cells with pyroninophilic cytoplasm. Cultures of unaffected rat monolayers were different, in that there was a prolonged survival of small lymphoctyes with the formation of lymphocyte aggregates in which large lymphoid cells appeared.

When large lymphoid cells from destroyed monolayers were transferred to new monolayers of the same type, a complete destruction of the monolayers occurred as early as 16 hours after cell transfer, but when transferred to an unrelated type, (from mouse to rat or fom an unaffected batch of rat to the other batch or to mouse), the monolayers were not destroyed. The destructive effect was transferrable by washed large lymphoid cells, but not by cell‐free medium. There was no monolayer destruction with adult rat thymus cells. Tests for a possible viral injection as a contributing cause to the monolayer destruction were negative.

The results indicate that a heterograft and a homograft response have been initiated in tissue culture by lymph node cells from unsensitized rats.
The cloning of normal “Mast” cells in tissue culture
Authors: Pluznik Dov H. , Sachs Leo
Published: February 2005

A method is described for the cloning of normal mouse “mast” cells in tissue culture in a soft agar medium. The colonies contain cells in different stages of differentiation. It was shown that a colony can be initiated by a single colony forming unit, and that colonies are formed as a result of cell multiplication.

Cell suspensions from adult spleen gave about 3 colonies per 105 cells seeded. A re‐cloning of these colonies gave about 3 colonies per 103 cells seeded.

The frequency of colonies from SWR mice was higher with adult spleen than with adult thymus. No such colonies were obtained with adult lymph node cells.

The formation of colonies was shown to require the presence of an embryo cell feeder layer. Since the feeder layers were seeded underneath the agar, the results indicate that the substance(s) required for the growth and differentiation of “mast” cells can pass through agar.
Molting in an amphibian, diemyctylus
Authors: Adolph E. F. , Collins H. H.
Published: February 2005

The shedding of epidermis in this species, as in most amphibia, is periodic. A single outer layer of cells separates nearly simultaneously over the whole body; two hours to ten days may be required for the process. In the first three months of laboratory existence the average frequency of molting was 9 per cent. In nature the frequency was only 2 per cent; this increased during the life in confinement in five months up to 25 per cent. Death in the laboratory was usually preceded by numerous molts.

The time of a molt is not normally determined by any one of a number of ordinary external conditions which were modified; but nevertheless several means were found of inducing molting. These were, in order of their efficacy: bandaging with gauze on body or tail, wrapping the body with thread, stitching the body wall, applying hot water, and transplanting skin. Molting frequencies up to 98 per cent may thus be obtained.

Since molting is periodic and simultaneous, it is evidently coordinated. Experimental induction requires a latent period of six to ninety‐six hours, depending upon the stimulus. Recent skin grafts molt with the host, so that the coordination is probably chemical. The primary significance of molting in all groups of animals is possibly the getting rid of unautolyzable waste materials, i.e., worn epithelial structures.
The reproductive system of apotettix eurycephalus hancock
Authors: Harman Mary T.
Published: February 2005

The female reproductive system comprises the ovaries, oviducts, vagina, spermatheca, and spermathecal gland. No colleterial glands are present. The ovaries are paired and each is composed of about eighteen ovarian tubules terminating in a cup‐shaped modification of the oviduct—the egg calyx. The epithelial lining of the oviduct is glandular. The spermatheca, a bladder‐shaped sac situated dorsal to and between the two ovaries, opens into the vagina near the exterior and is filled with spermatozoa after copulation. Spermatozoa have not been found in any other part of the female. Dorsal to the spermatheca and lying against it is the spermathecal gland. It is connected with the spermatheca by an elongate spermathecal duct.

The male reproductive system comprises the testes, vas deferens, accessory glands, and the penis. Each testis is composed of eight to ten cone‐shaped follicles, which are composed of a number of cysts so arranged as to appear segmented. All of the cells of each cyst are in approximately the same stage of development. No seminal receptacle is present. Each follicle is connected with the vas deferens by an efferent tube. The paired vas deferens opens into the sac‐like intromittant organ or penis. The terminal portion of the penis may be everted, and when everted is conical in shape. At its base is a thin chitinous collar, the margins of which are thickened, forming ridges.
The life‐cycle in the ciliate Didinium nasutum with reference to encystment
Authors: Beers C. Dale
Published: February 2005

Three groups of pure lines of diverse clones of Didinium nasutum were maintained in isolation cultures for 778, 786, and 457 generations, respectively, without exhibiting any decrease in fission rate or any increase in encystment rate or death rate. These lines were supplied with Paramecium caudatum in such numbers that a surplus of food was present at all times.

Three other groups of lines of the same clones were established simultaneously and cultured in parallel with the preceding groups, but the food of each of these lines was limited to nine paramecia per line daily. The fission rate of these lines fell to zero and the encystment rate increased to 100 per cent after 155, 165, and 113 generations of culture, respectively. The death rate increased appreciably in these lines prior to encystment.

Other groups of pure lines were cultured on a diet limited to six paramecia per line daily. These lines encysted after approximately fifteen generations of culture.

This evidence indicates that there is nothing in the nature of a definite life‐cycle in Didinium and that diminished vitality and encystment do not result from the passage of generations, but from inadequate and unfavorable cultural conditions–specifically, from in‐sufficient food. It shows further that it is possible to induce cycles with reference to encystment in Didinium by limiting the food supply and to vary the length of the cycles by varying the quantity of food.
Studies of the life‐cycle of Tetramitus rostratus Perty
Authors: Bunting Martha
Published: February 2005

The flagellate, Tetramitus rostratus Perty, appeared in cultures of certain amoebae obtained from the coecum of rats. In a typical life‐cycle a cyst, planted in an appropriate medium, gives rise to an amoeba which may divide a number of times, but eventually some of the amoebae transform into flagellates identical with Tetramitus rostratus. These divide frequently through several days, sometimes for weeks or months, and then transform back to amoebae which become encysted.

During excystment the smooth cyst wall dissolves. Usually both the amoeboid and flagellate phases pass into a “gel” state during division. A “gel” state sometimes occurs during transformation. The time required for transformations varies from a few minutes to several hours.

Many culture media and methods have been tested. In certain cultures the flagellate phase was prolonged for weeks or months. These cultures were characterized by: 1) great variation in size, from minute “dwarfs” to oversized “monsters”; 2) frequent multiple fission; 3) pairing and fusion, and, 4) some evidence for the origin of secondary nuclei from chromidia. In cases of pairing and fusion, the process of maturation and union of nuclei could not be definitely proved, although suggested by the observations.

The flagellate phase is more probably the “adult” phase because of its complex organization and possible sexual phenomena. This case is considered an extreme for this type amoeba‐flagellate transformation.
The comparative morphology of the secondary sexual characters of elasmobranch fishes the claspers, clasper siphons, and clasper glands. Memoir VIII
Authors: Leigh‐Sharpe W. Harold
Published: February 2005

Chlamydoselachus resembles the Holocephali in possessing no siphon, but a cavity in the proximal portion of the clasper. The cartilages, musculature, and venous sinuses of the clasper are considered. An older specimen of Echinorhinus is proved to have a spine on a soft papilla; Scymnus has no spine; both have the general features of the Spinacidae. Two species of Cestracion are compared with C. philippi. Mustelus lunulatus lacks the pera and pseudosiphon of M. vulgaris. Dicerobatis has a peculiar scaphus, and the claspers end in a fimbriated manner. Pteroplatea resembles Trygon and Benthobatis and Astrape are both like Torpedo.

The species are listed below.
The development of the thigh musculature of the chick twelve figures
Authors: Romer Alfred S.
Published: February 2005

The development of the thigh musculature in a series of chick embryos is described and figured. In the earliest the muscular tissue is in the form of two distinct masses lying on opposite surfaces of the limb. Later, both divide into proximal and distal portions at the knee. The proximal portions, by a series of divisions, gradually attain the condition found in the adult thigh.

The embryological findings tend to support the theory of the derivation of tetrapod limb musculature from the two opposed (dorsal and ventral) muscle masses of the paired fins of bony fish.

The reptilian homologies of the ilio‐trochanterici cannot be definitely ascertained from embryological evidence.

The ischio‐femoralis (= ischio‐trochantericus), Previously regarded as dorsal, and the coccygeo‐femorales, previously classed as incertae sedis, are in reality members of the ventral group.

The distinction between ‘intrinsic’ and ‘extrinsic’ muscles inserting on the free limb appears to have no embryological or phylogenetic basis in fact.

Double innervation (motor) is a primitive condition in tetrapods.

Rotation of the avian pubis is correlated with an improved functioning of the obturator in the rotated position coupled with a lack of interference with the other musculature concerned.
Ant‐mounds as to temperature and sunshine
Authors: Andrews E. A.
Published: February 2005

The ant Formica exsectoides F. builds mounds with some reference to sunlight, and measurements of internal temperatures have shown them higher in upper parts of the mound, but different in different faces of the mound—all higher than the earth outside the mound.

Inside temperatures are not constant; they are due to the sunshine. The mound is so fabricated that the internal temperatures are conserved during the night. The ants make use of the differential internal temperatures for rearing broods.

Some mounds show bilateral symmetry dependent upon sun exposure.

Measurements of rate of running of these ants show a falling off with lower temperatures, and possibly this is one factor in the smaller development of northerly aspects of these mounds.
Oogenesis in Limulus polyphemus, with especial reference to the behavior of the nucleolus
Authors: Gardiner Mary S.
Published: February 2005

A description is given of the cytoplasmic alterations in the ovarian egg of Limulus polyphemus leading to the formation of yolk. The nucleolus is found to arise by the confluence of substance which passes from the cytosome into the nucleus, and it is suggested that the chondriosomes, and possibly also the dictyosomes, are derived from an excess of this substance which accumulates in the cytosome. Chondriosomes and dictyosomes are not present in the oogonia, but appear first in oocytes after the formation of the nucleolus is completed.

During oogenesis the nucleolus is very active and the greater part of its substance is passed back to the cytosome. By the application of the method of Bell and Doisy for the determination of phosphate in body fluids, the nucleolus is found to be richer in phosphorus than are the other constituents of the cell. The nucleolar emissions effect the transport of phosphorus from the nucleus to the cytosome, where it is used in the synthesis of yolk. The definitive yolk arises by the interaction of nucleolar emissions, chondriosomes, dictyosomes, and ground cytoplasm.
Conjugation in the ciliate Metopus sigmoides C. and L
Authors: Noland Lowell E.
Published: February 2005

Conjugating individuals of Metopus sigmoides fuse at the anterior end, the pair presenting the appearance of an inverted letter U. The micronucleus of each conjugant by two successive divisions forms four micronuclei. Three of each four degenerate and the fourth by division forms the pronuclei. Cytoplasm and pronuclei from one conjugant pass over into the other, leaving the old macronucleus and a minimum of cytoplasm behind in the shrunken pellicle of the smaller conjugant, which then separates from the larger one. In the larger exconjugant two pronuclei fuse, forming the functional synkaryon; the two residual pronuclei degenerate and disappear. The synkaryon divides. One of the daughter nuclei condenses into the new micronucleus, the other grows into the new macronucleus. The old macronucleus liquefies and is absorbed. The larger exconjugant, after losing its cilia, secretes a cyst wall about itself and becomes dormant. The whole process requires at least six days for its consummation.
Spermatogenesis in the Belostomatidae. II. The chromosomes and cytoplasmic inclusions in the male germ cells of Belostoma flumineum Say, Lethocerus americanus Leidy, and Benacus griseus Say
Authors: Chickering A. M.
Published: February 2005

This paper contains a description of the appearance and behavior of the chromatin and chief cytoplasmic inclusions in the male germ cells of three species of Belostomatidae.

There are eight spermatogonial chromosomes in Lethocerus americanus, twenty‐four in Belostoma flumineum, twenty‐eight in Benacus griseus. An XY‐pair of sex chromosomes occurs in each species. These are identifiable at every step in maturation in Lethocerus, but not in the others. A clear case of heteropycnosis occurs in Benacus. Parasynapsis is believed to be the mode of pairing of chromosomes in all three species. The genesis of three large atelomitic ring tetrads is described in Lethocerus.

Chondriosomes are traced from spermatogonia to spermatids without a break in continuity. Spermatogonial chondriosomes are always granular. During the growth period filaments are formed, probably by fusion of granules, and these are sorted out in approximately equal numbers to spermatids. Benacus is especially favorable for studies on chondriosomes. Likewise, Golgi bodies have been traced throughout the process of maturation. They are minute granules in spermatogonia. During the growth period each becomes a flattened plate‐like body clearly differentiated into two materials. Dictyosomes are formed by fragmentation in the first prophase, and these are distributed to spermatids where they fuse to form an acroblast in each. Some minor cytoplasmic inclusions are briefly described.
Trends in evolution: A discussion of data bearing upon ‘orthogenesis’
Authors: Metcalf Maynard M.
Published: February 2005

Five characters–flatness, elongation, posterior pointedness, delay in division of the body, delay in completion of mitosis–are so distributed among the subdivisions of the Opalinidae as to involve either repeated fortuitous appearances of these characters, a thing not to be believed, or trends resident in the germ plasm. The Ophryoscolecidae show similar distribution of two sets of characters. In the Salpidae there is evidence of trends toward: coiling of the gut; decrease in number, size, regularity, and symmetry of body muscles; simplification and degeneration of the eyes. These qualities appear first in the phylogeny in the chain Salpas, the final phase in the life‐cycle. In the course of the evolution the solitary Salpas become more and more modified in the same directions, until, in the most highly modified species, the muscles and eyes are as much modified in the solitary Salpas as in the aggregated. These changes, not disadvantageous but rather adaptive in their beginning in the colonial individuals, are harmful to the solitary Salpas, yet the degeneration is, by precocious development, thrown back onto the earlier phase of the life‐cycle, the solitary stage. Precocious development is not purely utilitarian, but may be more fundamental, biological.

Evolution is discussed in terms of trends resident in the germ plasm, their origin in connection with mutations, their growth, decrease, disappearance, branching; auto‐evolution. Discussion is from the standpoint of the germinal stream, internal factors of evolution being emphasized.
A study of the chromosomes in meiosis, fertilization, and cleavage in the grasshopper egg (orthoptera)
Authors: McNabb Josephine Willis
Published: February 2005

A technique is developed whereby the large heavily yolk‐laden grasshopper egg may be sectioned for cytological study. Eggs of Chortophaga viridifasciata and Circotettix verruculatus were examined.

In C. viridifasciata the structure of the late ovarian nucleus and the chromosomes in meiosis, fertilization, and early cleavage are described. In the first maturation twelve rod‐shaped tetrads are found. Near the caudal end of the egg a polar body is given off, and in the second maturation division there are twelve dyads. At fertilization, twelve separated vesicles of the female pronucleus are seen scattered about a male pronucleus in which the chromosomes are in prophase.

In early cleavage the chromosome numbers in the metaphase are found to differentiate the male‐ and female‐producing eggs. In the former there are twenty‐three and in the latter twenty‐four chromosomes. A vesicular condition in which the chromosomes retain their boundaries in interkinesis is indicative of chromosome individuality.

A comparison of the first and second maturation metaphase chromosomes of the oocyte with those of the spermatocyte shows a similar compact group on the spindle, a likeness in size seriation, and a similarity of form. They differ in that in the spermatocyte complex there are eleven tetrads and one dyad. This latter, the unpaired sex chromosome, falls among the large chromosomes.

A comparison of the chromosome complex of Chortophaga viridifasciata with that of Circotettix verruculatus indicates constancy of generic differences in form, size, number, and behavior of the chromosomes.
Observations on the fat‐body in Hymenoptera
Authors: Schmieder Rudolf G.
Published: February 2005

An histological and cytological study of the postembryonic history of the fat‐body in Pteronidea ribesi (Scopoli) and Diphadnus appendiculata (Hartig) (both Tenthredinidae) and in Macrocentrus ancylivora Rohwer (Ichneumonidae).

The two principal components of the fat‐body are the urate‐storing excretory cells and the fat‐cells.

The development and behavior of the excretory cells, especially during the metamorphosis, are described, and in Pteronidea their origin is traced to leucocytes which have become associated with the fat‐cells.

In the albuminoid inclusions found in the fat‐cells two types of substance are distinguished: (a) a basophile material, of nuclear origin, which appears only during the metamorphosis; (b) an acidophile material which appears already during the early larval stages in Macrocentrus, but in Pteronidea is formed only during the metamorphosis and in association with the basophile material. It is thus found that albuminoids formed slowly during larval life may exist from the beginning in the form of acidophile spheres, as occurs in Macrocentrus. But those formed rapidly during the metamorphosis, in all the forms studied, are formed in association with a basophile material derived from the nucleus.

The significance of intracellular changes during the metamorphosis is discussed, and the final disposition of the cell inclusions as well as of the fat‐cells themselves is described.
A sexually mature turbellarian resembling Müller's larva
Authors: Heath Harold
Published: February 2005

This paper deals with the description of an organism, externally resembling Müller's larva among the polyclads, collected in the plankton of Monterey Bay, California, during the spring and summer months. Internally, the organization of the various systems is unique. In some respects it bears a certain resemblance to a polyclad in early stages of development; in other regards it approaches the rhabdoceles, more particularly the Acoela. Its more exact relationships are obscured by the fact that, although the larger specimens are not more than 0.7 mm. in length, the sex organs, both male and female, are fully developed and functional. Furthermore, the plan of these systems is unlike that of any turbellarian hitherto described. Whether this organism represents a case of paedogenesis or is a fully developed adult is unknown at present, but in any event the various systems are described and an attempt is made to give it a fairly definite systematic position.
The septomaxillary. I. In the amphibia urodela
Authors: Lapage Enid Oldham
Published: February 2005

The septomaxillary bone is described in the various families of the urodeles in which it occurs. Its identity as a hitherto unrecognized cartilage bone of the skull is established and its close relationship with the nasal muscles followed through the group. Its presence or absence, which is found to be another criterion for the recent classification of the urodeles as proposed by Dunn and Higgins, is correlated with the development of the accessory dilatator muscle, since it occurs only in groups where this muscle attains an appreciable size.
The morphology and physiology of the hepatopancreas of Cambarus virilis
Authors: Dorman Henry P.
Published: February 2005

The relation of the hepatopancreas to the pyloric stomach and its physiologic histology were studied. The organ consists of two lobes, united ventrally, which lie along the cardiac and pyloric stomachs and the intestine. Primary and secondary lobulations (acini) are present, and the entire organ is a system of anastomosing tubules (lumina). The tubules progressively converge and form a duct in each lobe which leads ventrolaterally into the pyloric stomach.

Each acinus consists of a single layer of hepatic and pancreatic cells supported by a basement membrane, and the interacinar spaces are the seat of fibro‐elastic tissue and phagocytic cells. The supporting tissue is laminar with that of the stomach. The arterial capillaries, composed of endothelial cells, lie in the interacinar spaces. The blood supply is by way of the basement membrane to the cells.

The hepatic cells of specimens collected in September bear little fat; cells of June specimens are laden with fat. Glycogen is deposited in the hepatic cells; there is no difference between the quantity found in September and in June. The hepatic cells probably contain biliverdin. Chemical analysis indicates the presence of trypsin, amylase, and lipase.

A review of the literature and a discussion of homologies with reference to the vertebrate liver are given.
Variations in chromosome number in the spermatogenesis of Philosamia cynthia
Authors: Dederer Pauline H.
Published: February 2005

A study of spermatogenesis was made on four groups of a pedigreed strain of the moth Philosamia cynthia, and the results were compared with spermatogenesis in the wild material.

Deviations from the normal number of chromosomes were observed in two groups. In some individuals the haploid number was 12 instead of 13. Giant spermatocytes were also observed with twenty‐four chromosomes. In other individuals, two haploid numbers, 13 and 14, occurred in the same testis.

The twelve‐chromosome condition is due to linkage of two chromosomes during the late prophase of the primary spermatocyte. The double chromosomes thus formed appeared to divide equally in both divisions. The origin of the fourteenth chromosome was not determined.

Correlation of the genetic and cytological data indicates the restriction of aberrant chromosome complexes to two of the four groups and the regularity of the twelve‐chromosome complex in certain families, suggesting the conclusion that a new strain arose in the pedigreed material with regard to chromosome variability and that the twelve‐chromosome condition is a well‐defined characteristic, partly established in some families and probably fully established in others.
The significance of the asymmetry of the ovaries of the fowl
Authors: Brode Malcolm D.
Published: February 2005

A chronological investigation of the histological condition of the right ovary of the domestic hen from embryos of nine days' incubation to adults of eighteen months was made. A rudiment of the right ovary is found at all times. Its composition is variable. Sixty‐one per cent of the rudimentary ovaries contained medullary tissue only. Thirty‐nine per cent had rudiments of cortex, in addition. The occurrence of cortical rudiments in embryonic stages is the probable basis of ovarian follicles found in the rudimentary right ovaries of adults. Primordial germ cells persist in the medullary tissue until three weeks after hatching. They subsequently appear to atrophy. The medullary cords persist through the entire period either as distended tubules or as solid cords of modified epithelial cells. Remnants of the right mesonephros persist as tubules and connect with the gonad by rete tubules. The mesonephric duct maintains a patent lumen.
Ecological studies of the seasonal distribution of protozoa in a fresh‐water pond
Authors: Wang Chia Chi
Published: February 2005

This study deals with the seasonal distribution of protozoa (February, 1927, to February, 1928) in correlation with seasonal fluctuations of temperature, hydrogen‐ion concentration, and the relative amounts of dissolved oxygen and other gases in a small fresh‐water pond. Twenty‐seven species of Sarcodina, thirty‐one species of Mastigophora, and 109 species of Infusoria were recorded in the surface water of the pond.

As found especially for Mastigophora and Infusoria, the number of species is inversely correlated with the abundance of individuals in the seasonal distribution.

Higher temperatures probably accelerated the rate of reproduction, since the seasonal maxima for most of the species were recorded in warmer weather.

Colonial flagellates and Zoochlorellae‐bearing ciliates seemed to be favored by higher oxygen content, with a simultaneous abundance of volatile acids, especially CO2. Although hydrogen‐ion concentration was limited between 6.2 and 7.05, it was probably one of the factors influencing protozoan distribution, since several species disappeared when the lowest pH was recorded. Sunlight is one of the important factors in bringing certain heliotropic protozoa to the surface.

The seasonal maxima of many of the protozoa occurred during September and October, 1927, when most of the observed physical environments seemed much more favorable than in other months.
On the development of imaginal buds in normal and mutant Drosophila melanogaster
Authors: Chen Tse‐Yin
Published: February 2005

Definite information concerning the time of development and location of the different imaginal discs of Drosophila melanogaster was needed in order to interpret especially the gynandromorphs, mosaics, and intersexes that have been extensively reported in cultures of this fly. This information was also desirable for many of the mutant types. It was not known, for example, when an organ was reduced or absent, whether its imaginal disc showed a corresponding reduction, or whether it was full size in the larvae and pupae, and failed to carry through to the later stages.

Three mutant types with eyes smaller than those of the wild type, namely, lozenge, bar, and eyeless, were examined. It was found that there is a corresponding difference in size as far back as the imaginal disc could be detected. Similarly for the two mutants, vestigial and no‐wing. Conversely for the mutant, bithorax, in which the metathorax is larger than the normal and has assumed many of the characters of the normal mesothorax, the imaginal disc was correspondingly enlarged.

It follows that the effects of the mutant genes for these characters can be observed in the very earliest condition of the imaginal disc.
Cytological studies on the spinning glands of platyphylax designatus walker (Trichoptera): Respective rôles played by the nucleus and the golgi apparatus during secretion
Authors: Beams H. W. , Wu C. F.
Published: February 2005

In sections the protoplasm of the spinning gland of Platyphylax designatus Walker appears to be a syncytium with large, branching nuclei, which contain both nucleoli and chromatin granules embedded in a delicate linin reticulum.

In the normal gland the nucleus is sharply marked off by a nuclear membrane from the granular, homogeneous cytoplasm. The Golgi apparatus appears as rings, loops, or comma‐like structures, evenly distributed and without orientation to the nucleus or lumen of the gland.

The nucleoli first increase both in number and size within the nucleus, then migrate out into the cytoplasm, where they undergo further growth, and finally are dissolved and passed out into the lumen of the gland as liquid secretion.

Small vacuoles appear near the periphery of the gland in early periods of activity.

In glands active for forty‐eight hours all stages of the secretory process may be seen.

In glands active for longer periods only vacuoles are present which we interpret as the remains of the secretory inclusions. There is a progressive decrease in the nuclear content of the nucleus.

Throughout the activity of the gland the Golgi apparatus changes little from the normal condition, both in form and distribution. As activity progresses, the bodies become smaller and slightly more dispersed. No relation of Golgi apparatus to the secretory phenomenon is apparent.
A study of the function of the epididymis. I. Is the attainment of full spermatozoon maturity attributable to some specific action of the epididymal secretion?
Authors: Young William C.
Published: February 2005

During the past few years many functions have been assigned to the epididymis which have been supplementary to its rǒle in sperm storage and to its secretory activity. One of these, the suggestion that sperm attain full maturity and are strengthened in consequence of some action of its secretion, has been reinvestigated as the first part of a study which is intended to include other aspects of the problem.

No evidence in support of the theory was obtained from a series of experiments on various mammals representing a repetition and extension of earlier work. On the contrary, the strengthening and attainment of full spermatozoon maturity would seem to be the outcome of changes which are inherent in the sperm themselves. It is suggested, therefore, until other aspects of the subject can be reinvestigated, that the epididymis is simply a reservoir for sperm in which the processes of sperm development which start while they are still contained in the testis are free to continue because of the favorable environment present in the epididymis.
The anatomical qualities of the liver during the various stages of its functional activities
Authors: Forsgren Erik
Published: February 2005

The liver has a rhythmic function with alternating assimilatory and secretory stages. The height of the assimilatory stage in rabbit's liver is characterized by the following qualities: All the cells are usually expanded and contain much glycogen and few bile components. The bile capillaries are narrow and generally empty. The glycogen content is high (about 13 per cent); the total glycogen weight is also high (about 17 grams). The liver has a relatively heavy weight (about 140 grams), a large volume, notably firm consistency, and a light brown color.

The secretory stage at its height has the following characteristics: All cells are shrunken and are rich in bile components, but contain little glycogen. The bile capillaries are expanded and filled with secretion (fixation with barium chloride). The glycogen content is low (about 1 per cent), and the total glycogen weight is also low (about 1/2 gram). Weight of liver low (about 50 grams). Volume small and consistency fairly flaccid. Color dark reddish brown.

Between these two extremes are various intermediary stages. Such variations as these probably occur during the normal functioning of the liver in man and also in other animals.
The structure and chromosomes of three gynandromorphic katydids (Amblycorypha)
Authors: Pearson Nathan E.
Published: February 2005

The external genitalia and the internal reproductive organs are described. Compound gonads, with a normal development of testicular and ovarian tissues, are found in the positions of the gonads of normal individuals. The genital ducts arise in both types of tissue and serve as common ducts.

It is demonstrated microscopically that the male tissue has one and the female tissue two sex chromosomes. The diploid number (or nearly so) is present in both tissues. This is the constitution of the normal sexes.

The origin of the gynandromorphs is accounted for by assuming either the theory of dispermy in the binucleated egg or chromosomal elimination.
The embryological basis of size inheritance in the rabbit
Authors: Castle W. E. , Gregory P. W.
Published: February 2005

A comparative study of the embryology of the rabbit in races of large and small adult size shows a consistently more rapid rate of cell multiplication and of increase in mass in large‐race embryos than in those of small race.

This more rapid rate of growth is transm tted by and influenced equally by sperm and egg cell, as is shown by the results of reciprocal crosses.

Rate of differentiation is independent of rate of growth and unaffected by it. Consequently, embryos of the large race have attained greater size than those of the small race at corresponding stage of differentiation.

The fundamental difference in rate of growth is already in evidence in forty‐eight‐hour embryos and becomes increasingly clear at later stages. Embryos produced by the large race have undergone about one more cell division at forty‐eight hours after mating and so are approximately in the thirty‐two‐cell stage when embryos of the small race are in the sixteen‐cell stage.
A cytological study of the proximal and distal tubules of the mesonephros of Necturus maculosus. (Under normal and experimental conditions)
Authors: Curry Laliah F.
Published: February 2005

The purpose of this study was to determine whether structural elements of the cytoplasm can be demonstrated to be specifically concerned with certain physiological processes that are experimentally induced in tissue at the time of fixation. The methods for bringing into view variations in cell structure correlated with cell activity were as follows: the increase of the process of secretion by subcutaneous injection into the living animal of phenol red and of urea; the increase of the process of reabsorption by injection of glucose: the inhibition of reabsorption of sugar by injection of phlorhizin.

Variations of the same magnitude in the form, position, quantity, and interrelationships of granules, globules, chondriosomes, and Golgi substance were found to occur in normal untreated animals and in those treated experimentally. Some evidence was found that in cells of the proximal tubule a characteristic form of Golgi body appears which seems to be correlated with increased reabsorption of sugar.