NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
22
Scientific Memoirs by
Owing, however, to the process of encystment being by far the most formi-
dable source of harm, and the impossibility of touching this by any drug,
remedial measures are of quite secondary importance compared with those of
prevention ; and here the course to be pursued is perfectly obvious, though
our success in following it must depend entirely on the means at our dis-
posal.
As it is perfectly clear that infection can only be spread through the
agency of the dung of affected animals, the exclusion of all equine animals
from the land from which our fodder is derived will alone suffice to stamp out
the disease. Hence, in large establishments, the acquisition of grass reserves
on which this measure can be carried out is of primary importance ; and, for large
stables, the establishment of cinerators, in which the dung of all animals may
be destroyed by fire, is a further measure that must suggest itself to all who
consider the question.
Again, I have experimentally ascertained that temperatures exceeding 140°F.
are fatal to the Rhabditis, and hence, where the establishment of protected grass
reserves is impossible, immunity may be secured by the exposure of all articles
of food to this very moderate temperature. For the private owner an apparatus
like the ordinary domestic " hot case " for warming plates and dishes would
suffice, while a moderately-sized room fitted so as to be well closed and provid-
ed with a furnace and flue would suffice for even large establishments. Such
a chamber would cost but little either to construct or to maintain, and would
amply repay the cost and trouble, in any country where large losses are refera-
ble to this disease. It is, by the way, a notable matter that Dr. Hendley informs
me that they found that cooking all the food, even to the grass of their equine
patients, by far the most effectual agent in treatment, and the fact of their
having been able to carry out the system, shows that the difficulties are by no
means insuperable.
I must now bring this paper to a close, and fear that I have already tres-
passed too much on the reader's patience, my only defence being that, though
it has run to a larger number of pages than I at all intended, I have done my
best to convey my meaning as briefly as possible.
Quite recently I noticed in the columns of one of the daily papers a notice
that the question of " Surra " was under examination in the new Bacteriological
Laboratory at Poona, and that their investigations had resulted in the discovery
of a " bacillus." I await with interest the publication of the results of this
investigation, which, if correctly reported, must imply the discovery of a class
of cases under the common designation of " Surra " of quite a different character
from those affected either by strongyles or by the Trichomonas Evansi, assum-
ing the latter, for the moment, to have a causal connection with some of the
cases so called.
I hope, however, the investigators will be careful to entirely exclude the
Medical Officers of the Army of India.
23
action of macroscopic parasites, by a systematic examination of the intestinal
canal and its walls.
SANAWAR ;
The 31st January, 1891.
G. M. GILES, M.B., F.R.C.S.,
Surgeon, I.M.S.,
In Medical Charge, Lawrence Military Asylum,
Sanawar.
Explanation of Plates.
FIG. 1.—Ovum of Sclerostomum tetracanthum from maternal oviduct.
,, 2.—Another in the stage of development usually met with in fresh horse-dung..
,, 3.
,, 4.
Further developed ova from cultivations ; the latter contains a well-deve-
‡ loped embryo.
,, 5.—Line 1/1000 "long on same scale as preceding figures, i.e., x 440 diams.
,, 6.—Recently hatched embryo. Those of the parasitic and free stages are quite
identical at this stage.
,, 7.—A further developed Rhabditis, 6 to 8 hours after hatching out.
,, 8.—Another specimen two days old. At A, a spindle-shaped body, the rudi-
ment of the generative gland, may be observed.
,, 9.—Scale of 1/1000ths" at same amplification as figs. 6, 7, 8, 10, 12 and 13
,, 10.—Very immature female Rhabditis, about a week old, from a cultivation in the
open-
i ,
i n t e s t i n e .
o, ovary.
v, genital aperture
,, 11.—Nearly mature male Rhabditis from forage plants.
,, 12.—Oral extremity of the same, more highly magnified, to show the peculiar
styloid mouth armature.
,, 13. Caudal extremity of the same to show the clasping spines
i ,
i n t e s t i n e .
f, spermatic duct.
c, c, clasping spines.
s, copulatory spicula.
,, 14. Scale of 1/1000ths" at same amplification as figs. 11 and 15.
,, 15. Mature female Rhabditis from forage plants. The specimen has almost co
m-pleted the process of laying her eggs, so that comparatively few ova (dis-
posed in single file) are left.
g, œsophageal ganglion.
p, pharyngeal bulb.
l ,
l e m n i s c u s .
i , i ,
i n t e s t i n e .
v, genital aperture.
,, 16. Immature specimen of parasitic stage from a submucous cyst. The genera.
tive gland is histologically indeterminate ; but the circumstance of the
most developed cells being placed in the middle of the gland shows the
specimen to be a young female.
,, 17. Scale of 1/100ths" at same amplification as fig. 16.
,, 18. Oral extremity of the same specimen, more highly magnified.
,, 19. Scale of 1/1000ths" at the same amplification as fig. 18.
PLATE. I.
G. M. G. de nat del.
Reg. No. 333, San., India.—Sept. 91.—300.
Litho., S. I. O., Calcutta.
Reg. No 333, San., India.— Sept. 9l.—300.
Litho., S. I. O., Calcutta
PLATE II.
G. M. G. denat del.
PLATE III.
G. M . G. de nat del.
Reg. No 333. San., India —Sept 91 —300
Litho., S. I. O. Calcutta.
On a new Sclerostome from the large intestine of mules (a
postscript to the preceding paper).
BY
SURGEON G. M. GILES, M.B., F.R.C.S.,
INDIAN MEDICAL SERVICE.
SINCE writing the above, a more careful examination of the materials ob-
tained from the mules that died in the so-called epizooty of " Surra " at Shillong,
has resulted in the discovery that the larger worms, found so abundantly in
company with Sclerostomum tetracanthum, are not, as I supposed, all large
specimens of that species, or of Sclerostomum equinum (Rud.), but examples of a
species which has not, so far as I can discover, been hitherto described.
Although they never rivalled S. tetracanthum in abundance, they were yet
so numerous that reflection should have shown that no large proportion of them
could be examples of S. equinum, as thousands must have been present in several
of the cases, and, to account for so large a number, the mesenteric arteries should
have been a mass of aneurisms ; whereas, in only one case, were these found,
and in this only two small ones, which could hardly account for the presence in
the intestine of more than a score or so of the mature parasites.
The species I am about to describe is intermediate in size between S. equi
-num and S. tetracanthum, averaging scarce half the length of the former, but is
proportionally very stout, and the characters of the mouth armature, and of the
bursa copulatrix are quite sufficient to establish its specific distinctness. As,
however, the three species are closely allied to one another, I append descrip-
tions, with original figures, of the other two, in order that their differences
and resemblances may be the more exactly appreciated.
The new species is a vicious blood-sucker, and was always found gorged
with blood, and generally firmly fixed to the mucous membrane. A very large
proportion are always to be found firmly joined together in pairs in copula, the
grip of the male hood being assisted by a glutinous secretion, so that it takes
some little careful dissection to separate them. As, in size, it bears at least as
large a proportion to the bulk of a horse or mule as Dochmius duodenalis
does to that of a man, and as it is often present in even larger numbers, it must be
capable, by mere depletion, of doing incalculable harm to its host, and it may be
doubted whether the caseous infiltration of the intestines brought about by
E
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Scientific Memoirs by
S. tetracanthum, combined with its weaker depletory efforts, had more to do with
the death of some of the animals examined than the loss of blood occasioned by
this larger species.
It is likely enough that this species too encysts, as all met with were
mature ; but the Trichonemes would probably be indistinguishable from those of
S. tetracanthum, which was always associated with it, and it would require a
case in which this species was alone present to establish this point, and to make
out any differences that may exist between their Trichonema stages. Their free
stage life-history is also probably similar ; but from the size I have recorded for
the ova, I am satisfied that it was at any rate mainly with S. tetracanthum that
my cultivations were concerned.
Description.—Sclerostomum robustum. sp. n.
Male about 13 mm. long by 0.8 mm. at the thickest part, which is situated about the
middle of the body.
Female about 22 mm. long by 1.1 mm. at the thickest part, which is a little in front
of the middle of the body.
The male is more tapered anteriorly than posteriorly, while the female is
equally so. Both sexes are usually tinged a rather deep reddish brown from the
blood on which they feed. Head subglobose, with a slightly constricted neck.
The margin of the oral aperture is irregularly tuberculated, and carries four
papillæ armed with soft setæ, which, from the large nerve fibres that can be
traced to them, are probably tactile in function. Within the tubercular margin is
a circlet of vertically placed denticles forming a trephine, like that of S. equinum,
only the teeth are much larger and less numerous (about 18). Within this,
guarding the oral aperture, are a series of horizontally placed fimbriæ (about 48
in number). These almost meet in the centre, so as to nearly close the opening
of the mouth. Below this, is a cup-shaped cavity which ends below in the open-
ing of the thick muscular pharynx, within the entrance of which are three
powerful, exactly similar teeth. Each of these teeth presents a falciform crown,
placed on a considerably longer and stouter root, which latter is fixed in a sort
of sheath-like pocket of the pharyngeal wall. They are probably capable of
being protruded.
The bursa copulatrix of the male is markedly bilobed, no trace of a median
lobe being present, though the dorsal fissure is not very deep. Ventral costa bifid,
combined with the ventro-lateral, and lateral costæ to form a group, the lateral
consisting of two subequal branches, with occasionally a smaller branch placed
near their roots on the dorsal edge of the costa. Dorso-lateral, and dorsal costæ
alike deeply bifid, and combined together to form a group of four, of which, the
most anterior division of the dorso-lateral is considerably the largest, while the
remaining three are subequal. Caudal extremity of female, rather abruptly
mucronate : anus close to the point of the tail : vulva about one millimeter in
Medical Officers of the Army of India.
27
front of it. Ova very large, of regularly elliptical outline, 0·152 mm. in length X
0.082 in breadth ; laid as a morula.
Sclerostomum equinum (Rud.)
I will first quote the description given in Diesing,1 a n d w i l l t h e n a d d s o m e
fuller details derived from the examination of a male specimen, from a verminous
aneurism of the mule :
—
" CAPUT globosum truncatum ; os limbo denticulis rectis dense armato.
CORPUS rectum retrorsum aitenuatum, bursa maris triloba, lobo intermedio
minore, lobis singulis quadriradiatis, radiis lanceolatis ; extremitate caudali
feminœ obtusiuscula, apertura genitali in tertia parte corporis postica. OVULA
elliptica medio constricta. COPULA sub angulo recto admissa.
Longit. mar., 1 "' ( 2 6 m m . ) ; f e m . 1 ½ — 2 "
" ( — 5 2 m m ) .
"
Unfortunately I was unable to find among my materials any mature intestinal
specimens ; but the specimen taken from an aneurism agreed in all points with
the above descriptions except ; of course, that, in length, it coincides with the
measurements he gives for his Var. Minor aneurismaticus. The most advanced
intestinal specimens of S. equinum that I have been able to discover among
my collections are still far from mature, and differ in no way save in size from
the aneurismal specimens described below. Only a very few ova approaching
maturity could be found, and these wanted still the median constriction, and had
evidently not reached their full size, being about the size of the ova Dochmius
duodenalis, measuring but 0·067 mm. in length.
In the specimen figured, the margin of the mouth carried six, nearly equi-
distant, tactile Papillæ, exactly similar in structure to those of the previous
species. On one side, showing through the skin, may be seen a long powerful
buccal tooth, shaped like a rat's incisor. Within the six marginal papillæ is
the circlet of the boring trephine, which is armed with minute, but proportionally
stout, semi-circular teeth. Within this again are the horizontal fimbriæ, guard-
ing the opening of the mouth, which are exactly similar in number and form to
those of the preceding species. The buccal cavity too is of nearly the same
form, though rather more funnel-shaped ; while the armature of the entrance
of the pharynx is quite different, and very peculiar.
This consists of two great teeth ; but, instead of being arranged at equal
intervals round the entrance of the pharynx, they are placed, one behind the
öther, on the same side. The outer tooth, the form of which has been already
described, is enclosed in a sheath, formed in the wall of the buccal cavity ; while
the inner tooth forms an unilateral projection from the margin of the opening of
the pharynx.
This latter is bidentate and nearly three times as wide as the outer tooth,
though less than half as long. It is very stoutly made, and carries on its axial
face a low ridge, irregularly tuberculated on both edges, running down from the
1 D i e s i n g : S y s t e m a H e l m i n t h u m ( 1 8 5 1 ) , V o l . I I , p a g e 3 0 3 .
E 2
28
Scientific Memoirs by
notch between the dentations, and broadening out below, where it meets the
circlet of denticles guarding the actual entrance of the pharynx. These last
consist of a circlet of chitinous plates, rather larger than those of the triphine,
but of very irregular shape, especially those on the side opposite to the great
tooth.
The male bursa copulatrix is, as will be seen from the figure, markedly
trilobed, the lateral lobes being rounded, while the median lobe is pointed,
though somewhat abruptly so. The ventral and ventro-lateral costæ form
a group almost exactly similar to that formed by the corresponding costæ of
the preceding species. The dorso-lateral consist of one large and one small
branch, which embrace between them the notch between the median and
lateral lobes; while the dorsal costæ are also represented by two branches, the
inner of which has a small rudimentary branch on its inner margin, rather nearer
its root than its point.
Sclerostomum tetracanthum Dies.
Descriptions. —This species differs considerably from the preceding, and
is, in some respects, more nearly allied to Œsophagostoma columbianum, an
ovine parasite, to be described below, as the cause of nodular disease of the
intestine in sheep. This resemblance is most marked in the arrangement of
the parts about the external mouth opening; but, at the same time the two
species cannot be considered to be congeneric, as the present species has a
shallow, but at the same time distinct, buccal cup ; whereas in Œsophagostoma
the armed peristome is followed immediately by the œsophagus.
Diesing's1 description is as follows :
—
" CAPUT truncatum; oris limbo interno denticulis rectis densis, externo
aculeis 4 majoribus obtusis cruciatim dispositis armato.
" CORPUS rectum utrinque attenuatum, bursa maris triloba, lobo intermedio
valde producto, lobis singulis multiradiatis, radiis furcatis ; extremitate caudali
fœminœ recta, truncata, breve mucronata, apertura genitali supra caudœ apicem.
Copula sub angulo recto admissa. "
This description is quite sufficient to identify the species ; but, for purposes
of contrast with the other species, the following details may be added :—
Cobbold2 remarks :—
" The fore-gut has a complicated structure, more strikingly so than has hitherto been
stated. The mouth leads into a strong buccal cup, supporting a circular series of short
bristles (described and figured by Schneider, but only indicated by a dark line in my
(Cobbold's) drawing), which separately have an extreme length of 1/760 of an inch. The
cup rests upon a muscular ring, which also supports a circular row (o 1 in the present
figure) of small chitinous processes. The ring is succeeded by an anterior œsophageal
bulb the lumen of which is bordered by chitin plates (o2 in the present figure).
1 DIESING : Loc. cit., Vol. II, page 305.
2 DR. T. S. COBBOLD.—Journal Linn. Soc., London, XIX, 1886, pages 284—93. It is remarkable
that Cobbold in this paper, which I have recently obtained, with true and scientific insight, actually foretells
as probable some of the points established in the preceding paper.
Medical Officers of the Army of India.
29
"Then follows a broad muscular pharynx ( p in the present figure), through which the
narrow, chitinous cylinder of the lumen ( sic) glimmers distinctly, leading down to the
somewhat broader posterior bulb, which also displays thick dental plates."
This description deals only within the mouth parts below the level of the
" straight denticles " (f in my figure) described by Diesing, Schnieder's series
of bristles being that marked ( b) in my figure. Thus we have from without
inwards-
First.—The four great labial spines, occupying the position of the tactile
papillæ of the other species, but forming, in this, formidable weapons.
Next comes the rank of horizontal fimbriæ, present in all three species, and
also in Œsophagostoma columbianum Curtice, described below. These fimbriæ
are very characteristic of the sclerostomes, and are often described as teeth.
They are, however, long thin plates, and do not in any way function as teeth, but
rather as a sort of sieve, between the plates of which blood corpuscles and
other fine particles suitable for food can pass easily, but which serve to exclude
all the coarser intestinal matter with which the animals are surrounded.
We now come to the buccal cup proper, armed with Schneider's Bristles,
and corresponding to the circlet of bidentate teeth of Œsophagostoma colum-
bianum. The boundary between the buccal cup, and Cobbold's anterior œsopha-
geal bulb is marked by a circlet of somewhat irregularly-shaped chitinous plates,
mostly rather broader at their free edges than at their origin and, in the same
way, the junction of the bulb with the pharynx is marked with a second row
of more regularly shaped plates, each of which consists of a flat, stout plate, of
semi-circular outline, with a small tubercle forming a point to the crown.
The ova of S. tetracanthum have a very characteristic oblong outline, rather
exaggerating the flattened sides, in fact, of Dochmius duodenalis, but are much
larger, measuring 0·1 x 0·05 mm. They are usually laid as a many-segmented
morula. Large as they are, they cannot possibly be mistaken for the very
much larger and elliptical eggs of the new S. robustum.
The form of the male bursa varies considerably, while always remaining of
the same type.
There is no distinct notch between the lateral and median lobes, as in S. ar
-matum ; but the median forms a bold curve back from the laterals and, especially
in small specimens, is often prolonged to a long point. In other specimens
again the median lobe is comparatively short and blunt. I . figure two specimens,
illustrating this variability, and neither is an extreme instance of the forms they
represent. With this variability the relative lengths of the dorsal and lateral groups
of rays also vary. Their arrangement, however, remains the same, the dorsal
costæ being bifid, the outer divisions considerably shorter. They form, with the
simple dorso-lateral, a distinct group.
The lateral, ventro-lateral and ventral costæ form two other compact,
paired groups, in which the anterior division of the bifid lateral far exceeds the
3o
Scientific Memoirs by Medical Officers of the Army of India.
other members of the group in size. Between the dorso-lateral and lateral
costæ are deep and broad semi-circular hollows, which are occupied, on either
side, by a single large granular cell, probably of glandular character. I can
find no previous notice of this gland cell, which is very easily seen in many speci-
mens, and can only with difficulty be made out in others, its variable prominence
probably corresponding to various stages in its secretive functions ; the
cell full of secretion being easily visible, while that which has recently dis-
charged its contents being with difficulty so. In connection too with variations
in the bursa, it may be mentioned that Cobbold ( loc. cit. ) mentions the occa-
sional presence of an additional branch to the dorsal costæ, which may be nearly
as long as the primary branch itself.
The figures given in the plates are all from original camera lucida draw
- i n g s , a n d c a n t h e r e f o r e b e t r u s t e d f o r t h e p u r p o s e o f o b t a i n i n g m e a s u r e m e n t s o f
the various parts represented. Combined with the foregoing descriptions I do
not think that any difficulty need be found in distinguishing the three species ;
nor do I think that any doubt can be felt of their specific distinctness.
At the same time, while to minute examination the differences are suffi-
ciently obvious, it is by no means easy to distinguish between the three
species by mere naked-eye examination. Between full-sized specimens of
S. equinum on the one hand, and small specimens of S. tetracanthum on
the other, S. robustum is easily distinguishable ; but, in all three species the
range of size is so considerable that it is extremely difficult to separate large
specimens of S. tetracanthum, and immature intestinal S equinum from the
newly described species : indeed, short of absolute dissection and microscopical
examination, I believe it to be impossible to do so. As a good naked-eye
method of distinguishing between S. robustum and immature S. equinum, I
may mention that the latter are usually much darker in colour, the small deve-
lopment of the generative organs permitting the blood filling the intestinal
canal to be seen more easily through the skin than is the case with the mature
S. robustum of the same size, where the intestinal canal forms but a very small
proportion of the bulk of the body.
It is doubtless owing to its close external resemblance to the two species
so commonly associated with it that it has not hitherto been recognised as a
distinct species ; and I shall not be surprised to hear that, now that attention has
been directed to the point, it will sooner or later be found that its distribution
is by no means confined to India.
G. M. GILES, M.B., F.R.C.S.,
Surgeon, Indian Medical Service.
SANAWAR :
The 21st November 1891.