NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
52
the bulb, but they do not describe how the separation between the labral and
epipharyngeal portions of the organ occurs, and I have been unable to deter-
mine this point for want of series of sections. It is a little unlikely that
labrum and labium would unite directly. From the fact that the section shown
in their figure 25 includes the attachment of the palp, one would suppose that
the section is an oblique one, through the lower end of the rostrum, in which
case the anterior membraneous portion is really the anterior wall of the
rostrum. It is, as a matter of fact, extremely difficult to get the rostrum and
haustellum sufficiently into line with one another to get a series of transverse
section of both, as I found in the case of Lyperosia. It would be still more
difficult to do it with Glossina, in which the angle is a much more permanent
one.
I have never myself seen Glossina in the act of feeding, nor is the oppor-
tunity likely to occur. I have selected from the numerous descriptions of its
mode of feeding one by an observer who presumably had no expert knowledge
of the subject, and merely recorded what he saw. It accords so well with what
I believe to be the mechanism of the proboscis that I cannot forbear from
quoting.
Captain Crawshaw writes as follows in 1896: " When a 'Tse-tse ' settles
"with the intention of feeding............he inserts his proboscis, lowers his head,
" and raises his abdomen till it is almost vertical ; when doing this and for some
"time after he has commenced sucking, he works his wings, buzzing in a minor
" key, rather like a bee when held forcibly, though not so powerfully ; when the
" keenness of his appetite has been somewhat appeased, he stops working his
" wings and sucks in silence. If left to himself he will suck until...
. . . . . . . . . . . . . " T h e r a i s i n g o f t h e a b d o m e n i s r e n d e r e d n e c e s s a r y i nG
l o s s i n a
b y t h e f i x a t i o n
of the joint between the rostrum and the head. It does not occur in S tomoxys.
The period during which the fly produces the buzzing sound is that in which the
wound is being made and the proboscis thrust into the skin, and while this
is going on the fly is not absorbing food. The motion of the wings and
the buzzing sound are produced by the excessively rapid respiratory move-
ments which distend the hæmatocœle with blood ; this must occur after
each contraction of the muscles of the bulb, in order that the teeth may be
replaced in position for the next cut, as explained in connection with Lyperosia.
I have never distinguished any sound produced by Stomoxys while inserting its
proboscis, but a faint vibration of the wings can be seen. The eversion and
replacement of the cutting teeth in Glossina must of course occur with very
great rapidity. As I have noted elsewhere, the cutting apparatus of the
Diptera is a good example of the extraordinary rapidity of action of which
insect muscle is capable. It is possible that by ascertaining the exact pitch of
53
the note one could fix definitely the number of contractions made per second by
the muscles of the bulb, for there will of course be one contraction for each
respiratory movement, and it is these respiratory movements which produce the
vibration in the wing.
When the wound has been made to a convenient depth the buzzing ceases,
the labella are held in a permanently everted position, and in a very short time
the fly sucks up enough blood to distend the abdomen. The motion of the
wings does not cease, as Captain Crawshaw supposed, when the appetite is
appeased, but at the moment the fly commences to suck, and is no longer
occupied in making the wound. The length of the narrow part of the proboscis,
the extremely efficient nature of the biting parts, and the rapidity with which
the abdomen distends with blood, make it probable that the fly gets well below
the epidermis and into a vascular layer before commencing to suck.
In several other accounts it is stated that the bite of Glossina causes pain,
not at the moment the fly settles down, but after a short interval. One inter-
prets this, as in the case of the mosquito bite, as due to the fact that it is the
saliva injected into the wound which causes the pain, and not the actual
making of the wound. The cutting parts of Glossina are so small and so sharp
that one would not expect them to cause pain.
54
Summary and Conclusions.
1. The blood-sucking Muscidæ are descended from a Musca-like ancestor.
The entomological facts make it improbable that the flagellates found in
the alimentary tract of blood-sucking flies, and of non-blood suckers which are
allied to them, are derived from the parasites in vertebrate blood. They are
probably the descendants of parasites which entered the alimentary tract at the
time the ancestors of the flies were mandibulate and omnivorous.
2. The first steps in the evolution of the blood-sucking habit can be seen at
the present day in those flies which are blood-suckers but have no biting mouth
parts. These depend on true biting flies for the making of the wound.
3. In the genus Philæmatomyia there are three species which show separate
steps in the modification of the Musca-like proboscis to a biting apparatus. The
changes all depend on the increase in size and functional importance of the presto-
mal teeth. They are:—Increase in the strength of the discal sclerite; separation
of the axial apophysis and labellar rods, and displacement upwards of the former;
approximation of the bases of the teeth and the separation of their bases from
the discal sclerite, to allow of greater freedom of movement; displacement of
the teeth to the distal end of the labellar rods; consolidation of the anterior
joint between the labial gutter and the discal sclerite; great increase in the
strength of the labial gutter and the development of a "keel" to provide addi-
tional attachment for the muscles; some consolidation of the posterior joint
with a thickening of the furca; increase in all the muscles; some diminution in
extent of the pseudotracheal membrane and the development of the interdental
armature from the rings of the pseudotracheæ.
4. Between the genus Philæmatomyia and the Stomoxydinæ there is a wide
gap. Future research will probably reveal other forms intermediate between
these.
5. In the S tomoxydinæ the proboscis is a piercing one in the true sense of
the word. Its spindle shape is due to the increase in extent and alteration
in shape of the mentum as seen in Musca, and to the diminution in the size of the
labella. The biting apparatus is altered upon the following lines:—The teeth
are reduced in number and in size; the interdental armature, which takes on
the filtering function of its homologue, is highly developed; the discal sclerite is
altered to a funnel-shaped piece; the articulation between the discal sclerite and
the labellar rods is more or less fixed in the position of extension; the posterior
joint becomes of great importance, and the furca and the arms of the fork
of the mentum are both greatly increased in thickness and reduced in size; not-
withstanding the chitinisation of the rest of the wall of the haustellum, there is
55
a membraneous interval left in the region of the joint which permits the furca
to be rotated freely backwards.
6. In all the flies dealt with, in the order given, there is an increase in the
relative length of the haustellum, and a diminution in that of the rostrum,
together with some diminution in the amount of movement between the latter
and the head capsule.
7. Glossina represents an extreme case, and there is a wide interval
between it and the Stomoxydinæ. The alterations in the shape and the diminu-
tion in the amount of movement are the same in kind as in Stomoxys, but in
greater degree. The teeth are more complex, and the interdental armatures are re-
presented by the "fans." The cutting apparatus is not limited to the inner wall
of the labellum, but extends on to the outer wall as well, and when the muscles
of the bulb contract the outer wall is pulled bodily upward as the inner wall is
everted. The discal sclerite is fused with the end of the labial gutter and
cannot be recognised as a separate sclerite. The furca and the two arms of the
fork of the mentum are closely approximated to one another. The main support
of the narrow piercing part of the proboscis is the labial gutter, which is very
strong, while the mentum in this region is semi-membraneous. The rostrum
is capable of so little movement on the head that the fly has to raise itself on
its hind legs to bring the proboscis into position for piercing.
56
References.
Austen, E. E. Monograph of the Tse-tse Flies. Brit. Mus., London, 1903.
Austen, E. E. Ann. Mag. Nat. Hist. (8) iii, page 295, 1909. (Original description of the
genus Philæmatomyia.)
Brunetti, E. Revision of the Oriental Blood-Sucking Muscidæ. Rec. Ind. Mus., Vol. IV,
No. 4, 1910.
Cragg, F. W. Studies on the Mouth Parts and Sucking Apparatus of the Blood-Sucking
Diptera. No. 1, Philæmatomyia insignis, Austen. No. 3, Lyperosia
minuta, Bezzi. Scien. Mem. by Officers of the Med. and Sanit. Departs.,
Govt. of India, N. S, Nos. 54 and 59, 1912.
Crawshaw, R. Letter quoted in Austen's Monograph, vide supra.
Graham-Smith, G. S. Some Observations on the Anatomy and Function of the Oral Sucker
of the Blow-Fly (Calliphora erythrocephala). Journal of Hygiene,
Vol. II, No. 3, November 1911.
Hansen, H. J. The Mouth Parts of Glossina and Stomoxys. Chapter V in Austen's Mono-
graph, vide supra.
Kraepelin, K. Zur Anatomie und Physiologie des Russels von Musca. Zeit. fur Wiesensch
aftliche Zoologie, B. 39, 1883.
Minchin, E. A. Discussion on the Hæmoflagellates, reported B. M. J. Nov. 9th, 1907.
Newstead, R. Insects and other Arthropoda collected in the Congo Free State. Ann. of
Trop. Med. and Paras., Vol. I, No. 1, pages 78 and 79, 1907.
Patton, W. S., and Cragg, F. W. The Genus Pristirhynchomyia, Brunetti. Ann. of Trop.
Med. and Para., Vol. 5, No. 4, 1912.
Prowazek, S. Die Entwicklung von Herpetomoras. Arbeit. Kaiserl. Gesund B. 21, 1904.
Rouband, E. La Glossina palpalis, Sa biologie, son rôle dans l'étiologie des Trypanosomiases
Thèse de Doctorat ès Sciences Naturelles, Paris, 1909.
Stephens, J. W. W., and Newstead, R. The Anatomy of the Proboscis of Biting Flies. I
Glossina, Memoir XVIII, Liverpool School of Tropical Med., 1906
II. Stomoxys, Ann. of Trop. Med. and Para., Vol. I, No. 2, 1907.
PLATE I.
Figure 1.—The proboscis of Philaematomyia insignis, Austen, from a cleared preparation
p., the palp. ap., the apodeme. fu„ the fulcrm. m., the membrane of the
wall of the rostrum. L.ep., the labrum-epipharynx. Hy., the hypo-
pharynx, L.g., the labial gutter. Th., the memtum (theca). L.K., keel
of the labial gutter. L.R., the labellar rod. T., the teeth. Pt. M., the
pseudotracheal membrane. T.f., fork of the mentum, Fr., the furca.
D.S., chitinous plates in the outer wall of the labella, reflexed x 33.
Figure 2.—The proboscis of Lyperosia minua, Bezzi, from a cleared preparation. f., the
posterior cornu of the fulcrum. f'., the anterior arch of the fulcrum. f".,
the funnelshaped distal end of the fulcrum. s.d., the salivary duct. ap.,
the apodeme. b.c., the buccal cavity. tr., trachea. l.g., the labial gutter.
mt., the mentum. b., the bulb, l.g., the labial gutter. m. a., the
membraneous area which allows of rotation backwards of the furca.
v . s c . , v e n t r a l s c l e r i t e s ( t h e p r o x i m a l p o r t i o n o f t h e f o r k o f t h e m e n t u m ) . f u . ,
furca. lb., the labella x 160.
PLATE I.
Fig. 1.
Fig. 2.
Photo.-Engraved & printed at the Offices of the Survey of India, Calcutta, 1913.
PLATE II.
Figure 3.—The mentum and furca of Musca nebulo. m., mentum. i., the incision in its distal
border. f., the proximal joint of the arm of the fork. f'., the distal joint, in
apposition with the furca. fu., the furca. p. s., the posterior plate of thin
chitin continuous with the membraneous part of the wall of the labella.
Figure 4.—The anterior wall of the haustellum of Musca nebulo, with the discal sclerite
attached. hy., the hypopharynx partially fused with the membraneous
anterior wall of the labium. m., the membrane which connects the mentum
and the labial gutter. l.g., the labial gutter. l.r., the lateral rods. d.s.,
the discal sclerite, articulated with the lateral rods of the labial gutter.
Figure 5.—The labrum-epipharynx of Musca nebulo. 1. , l abrum. ep., the epipharynx. ap.,
the labral apodemes.
Figure 6.—Two of the prestomal teeth of Musca pattoni, with the terminal rings of one of
the pseudotracheæ between them. t., tooth. ch. r., the chitinous filaments
supporting the end of the channel. r., pseudo-tracheal ring. d.s., the
discal sclerite.
Figure 7.—The prestomal teeth and terminations of the pseudotracheal channels of Musca
domestica, after Kraepelin. t'., t". t"' teeth of the first, second and third
rows. p. s., the pseudotracheal channels. d.s., the discal sclerite.
Figure 8.—The teeth and terminations of the pseudotracheal channels of Musca convexi frons
. t., prestomal teeth. p.s., the pseudotracheal channels. ch. r., the chitinous
rods surrounding the terminations of the channels. d.s., the discal sclerite.
Figure 9.—The termination of a pseudotracheal channel in Philæmatomyia gurnei. p.b. the
petiolated blades. p.s., the pseudotracheal channel. Note how the rin
gs split at the proximal end; just distal to this they are much elongated.
x 500.
Figure 10.—Some of the pseudotracheal rings of Philæmatomyia gurnei at a point distal to
those of the last figure. x 500.
Plate II.
Fig.3.
Fig. 4.
Fig.5.
Fig.6.
Fig.7.
Fig.8.
Fig.9.
Fig.10.
P h o t o . - E n g r a v e d & p r i n t e d a t t h e O f f i c e s o f t h e S u r v e y o f I n d i a , C a l c u t t a , 1 9 1 3
PLATE III.
Figure 11.—The proboscis of Hæmatobia irritans. b., the bulb. lb., the labella. ap., the
labral apodeme of one side. fa., the fulcrum. b.c., the buccal cavity.
p, the palps. x 80
Figure 12.—The labellum of one side, seen in profile. The position of the teeth is
indicated by the dotted lines. f.l., the flaps at the distal end of the pro-
boscis. p.s., the position of the channels on the inner wall of the flaps.
p.b., the position of the petiolated blades. t., the position of the teeth. l.g,,
the labial gutter. fu., the furca. m.f., the proximal arm of the fork of
the mentum. m.f'., the distal arm, detached and displaced forward. m.,
the mentum. x 180
Figure 13.—The external wall of one of the flaps, to show the shape and disposition of the
squamæ, and the area over which they are deficient. x 1100.
Figure 14.—The internal wall of one of the flaps, to show the pseudotracheal channel and the
sense hair at its termination. x 1100
Figure 15.—The upper end of the labial gutter, as seen in profile in a detached cleared pre-
paration. This is the same preparation as the next figure, but as seen at a
higher focus. The shaded portion represents the lateral expansion of the
gutter, the dotted lines indicate the outline as seen in the next figure.
Figure 16.—As above, at the lower focus.
Figure 17.—The upper end of the buccal cavity, to show the method of junction with the
pharynx. r., chitinous rings like these found in the salivary duct. ph.,
the lower end of the pharynx. x 310
Figure 18.—The first tooth in outline, to show the secondary teeth. x 700
Figure 19.—The fourth tooth. x 700
Figure 20.—One of the rod-like hairs, showing the central canal.
Figure 21.—Some of the rings of the pseudotrachea, showing the transition between the flat-
tened plates as seen in the flaps and the typical rings as seen near the
petiolated blades. x 1100
Fig. 16.
Plate III.
Fig. 11.
Fig. 12.
Fig.13.
Fig.14.
Fig. 15.
Fig. 17.
Fig.18
Fig.19.
Fig, 20.
Fig. 21.
Photo.-Engraved & printed at the Offices of the Survey of India. Calcutta, 1913
PLATE IV.
Figure 22.—The teeth and connected structures of Hæmatobia. The first tooth is on the left
of the drawing. r.h., rod-like hairs. p.b., petiolated blades. p.s., pseudo-
tracheal channels. Note the attachment of the teeth to one another at their
bases. They are attached to the edge of the discal sclerite by a band of
fibres, not shown. x 700
Figure 23.—The teeth and connected structures of Philæmatomyia gurnei. The anterior and
internal angle is on the right. t.p., the tooth plate. p.b., the petiolated
blades, between which lie the pseudotracheæ, as shown in Plate II, figure
9. x 475
Figure 24.—The discal sclerite and the teeth of Philæmatomyia lineata, seen from the side.
t., the prestomal teeth. p.s., the pseudo-tracheal channels. i.a., the chit-
inous rods embracing the terminations of the channels, and constituting the
interdental armature. r.t., the rudimentary tooth. c.c., the anterior
collecting channel. c.c'., the posterior do. t.p., the tooth plate, a flange
of the discal sclerite, d.s. l.r., lateral rod of the labial gutter. lb.r.,
labellar rod. x 600
Plate IV.
Fig.22.
Fig.23.
Fig. 24.
Photo.-Engraved & printed at the Offices of the Survey of India, Calcutta, 1913
PLATE V.
Figure 25.—The discal sclerite and the distal end of the labial gutter of Hæmatobia. x 400
Figure 26.—The same of Stomoxys. x 400
Figure 27.—The discal sclerite of Musca nebulo, seen from the front. x 340
Figure 28.—The same, seen from the side. x 340
Figure 29.—The discal sclerite of Philæmatomyia insignis, seen from the side. x 130
Figure 30.—The discal sclerite of Philæmatomyia gurnei, flattened out and seen from the
front. Camera lucida drawing. The faintly shaded area on each side of
the axial apophysis is the fractured portion. x 224, vide page 24.
Figure 31.—The discal sclerite and the terminations of the labial gutter of Philæmatomyia
lineata. x 300
Figure 32.—A photograph of the specimen of Philæmatomyia gurnei referred to in the text.
I am indebted to Major Kirkpatrick, I.M.S., for this photograph. x 30
Reference letters :—ax. p., axial apophysis. lb.r., labellar rod. l.r., lateral rod of the labial
gutter. m.g., the medium portion of the gutter. t.p., the tooth plate.
Fig. 28.
Fig.29.
Plate V.
Fig.25.
Fig.26.
Fig,30.
Fig. 31
Fig. 32
Photo.-Engraved & printed at the Offices of the Survey of India, Calcutta, 1913 .
ANNUAL REPORT
OF THE
BENGAL VETERINARY COLLEGE
AND OF THE
CIVIL VETERINARY DEPARTMENT, BENGAL,
FOR THE YEAR
1920-21.
CALCUTTA:
THE BENGAL SECRETARIAT BOOK DEPOT.
1921.
[Price, 15 annas.]
ANNUAL REPORT
OF THE
BENGAL VETERINARY COLLEGE
[INCLUDING THE REPORTS OF THE EPIZOOTIC DISEASES OF ANIMALS
DEPARTMENT IN CALCUTTA AND ITS VICINITY AND
THE RAYMOND RESEARCH LABORATORY.]
FOR THE YEAR
1920-21.
CALCUTTA:
THE BENGAL SECRETARIAT BOOK DEPOT.
1921.
(Maximum limit, 4 pages.)
TABLE OF CONTENTS.
Preface-General Administration . . . . . . . . . .
Veterinary Instruction . . . . . . . . .
Treatment if Discase . . . . . . . . . . . .
Breeding Operations .
.
.
.
.
.
.
.
.
.
.
Subordinate Establishment . . . . . . . . . .
Expenditure of the College . . . . . . . . .
General Remarks . . . . . . . . . . .
Epizootic Diseases of Animals Department, Calcutta . . . . . . . .
Raymond Research laboratory . . . . . . . . .
APPENDICES.
Table I
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
Appendix A . . . . . . . . . .
PAGE.
1
1-2
2-3
3
3
3
3
3-4
4
i
ii
2A
BENGAL VETERINARY COLLEGE.
Preface—General Administration.
I held charge of the Bengal Veterinary College, the Epizootic Diseases of
Animals Department in Calcutta and its neighbourhood and the Raymond
Research Laboratory throughout the year except from 1st July to 30th
September 1920 when I was on furlough.
Mr. P. J. Kerr, who joined the College as Second Imperial Officer on the
26th March 1920, was in charge of the College during my absence.
2. I acted as a "Member of the Examining Board" of this College in
March 1921.
3. During the year under report the Civil Veterinary Department,
Bengal, has been transferred from the administrative control of the Director of
Agriculture, Bengal, and, as Senior Veterinary Officer of the Province I have
been declared as "Head of the Civil Veterinary Department, Bengal," under
the designation of the "Veterinary Adviser to the Government of Bengal,"
with effect from the 1st November 1920. in pursuance of the policy recently
enunciated by the Secretary of State for India.
4. Also on the recommendation of the Public Service Commission, the
Government of India have been pleased to authorise the Government of
Bengal to settle the grading of the pay of the Provincial Veterinary Services
within the limits of pay fixed by the Secretary of State.
Veterinary Instruction.
5. Class A.—This class consisted of 43 students composed of 38 new
students and 5 plucked students of last year. All went up for the annual
examination and 26 passed, a percentage of 60.
6. Class B.—This class consisted of 38 students composed of 33
promoted from class A and 5 plucked students of last year. All went up for
the examination and 25 passed, a percentage of 66.
7. Class C.—This class consisted of 46 students composed of 35 pro-
moted from class B and 11 plucked students of last year.
Forty-five
students appeared at the examination and 24 passed, a percentage of 53.
8. At the beginning of the session, 161 students were on the rolls in the
three classes. Thirty-four withdrew their names from the College register.
Eighteen left the College early in the session of their own accord as
they did not find the profession to their liking. Seven withdrew on the
ground of ill-health. Nine joined the non-co-operation movement and left
the College. Thus leaving 127, of whom 53 belonged to Bengal, 45 to Bihar
and Orissa, 12 to Assam, 8 to United Provinces, 3 to Burma, 2 to Ceylon, 1 to
Madras, 1 to Central Provinces, 1 to Feudatory State Gangpur and 1 to
Manipur State.
Of these 81 were Hindus, 37 Muhammadans, 4 Budhists and 5 Indian
Christians.
Among the students 47 were matriculates.
9. Out of 24 newly-passed graduates, 4 belonged to Bengal, 10 to Bihar
and Orissa, 6 to Assam, 3 to United Provinces and 1 to Ceylon.
10. The examinations began on the 10th and terminated on the 19th
March. The Examining Board was composed of Mr. D. A. D. Aitchison,
Principal, Madras Veterinary College, as President, and Captain P. B. Riley,
Second Supeintendent, Civil Veterinary Department, Bihar and Orissa,
Mr. W. Harris, Superintendent, Civil Veterinary Department, Assam,
Mr. P. J. Kerr, Superintendent, Civil Veterinary Department, Bengal, and
myself as members.