NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
Dr. S. K. Das, L.M.P. (Rgn.)
Demonstrator in Anatomy,
Medical School, Rangoon.
Junior Hostel Master, Medical School, Rangoon Assumed charge on
the forenoon of 16th
January 1941.
P. K. Bose, L.M.P. (Rgn.) L.T.M. Demonstrator in Pathology,
Medical School, Rangoon.
. . . . . .
Assumed charge on
the afternoon of 15th
July 1940. On leave
from the forenoon of
12th February 1941.
Dr. G. L. Chowdhuri, M.B. (Cal.),
M.R.C.P.E , F.R.F.P. & S.
(Glas.), D.T.M. & H. (Edin.).
Third Physician, General Hospi-
tal, Rangoon.
Lecturer in Materia Medica, Medical School,
Rangoon (Honorary). Lecturer in Materia
Medica and Pharmacology, Medical College,
Rangoon.
Dr. Ba Than, M.B., (Cal.),
F.R.C.S.E.
Third Surgeon, General Hospital,
Rangoon. Also Police Surgeon,
General Hospital, Rangoon.
Lecturer in Medical Jurisprudence, Medical School,
Rangoon. Lecturer in Forensic Medicine,
Medical College, Rangoon.
Dr. K. T. Jungalwalla, L.M. & S.
(Bom.), F R.F.P. & S. (Glas.),
D.P.H., D.T.M. & H.
Assistant Director of Public
Health, Burma.
Lecturer in Hygiene, Medical School, Rangoon.
Lt.-Col. R. H. Malone, L.R.C.P. &
S. (Edin.), M.D., D.P.H.
(Mcgill.), I.M.S.
Pathologist, General Hospital,
Rangoon.
Lecturer in Pathology, Medical School, Rangoon.
Professor of Pathology, University of Rangoon.
APPENDICES.
11
ANNEXURE I—concld.
List of Staff—concld.
Name of the Staff.
Substantive Appointment.
Part-time Teaching Appointment.
Remarks.
(1)
(2)
(3)
(4)
Lt.-Col. C. de C. Martin, M.D.,
M.B., Ch.B. (Edin.), I.M.S.
Civil Surgeon, Rangoon (East).
Also Second Physician, General
Hospital, Rangoon.
Lecturer in Medicine, Medical School, Rangoon
Dr. M. N. Menon, M.R.C.S. (Eng.),
L.R.C.P. (Lond.)
Assistant to the Second Physi-
cian, General Hospital, Ran-
goon.
Tutor in Medicine, Medical School, Rangoon
(Honorary). Lecturer in Contagious Diseases,
Medical School, Rangoon.
Assumed charge from
the forenoon of 17th
June 1940.
Lt.-Col. H. Aung Khin, M.B., Ch.B.
(Edin.), F.R.C.S.E., I.M.S.
Civil Surgeon, Rangoon (West).
Also Second Surgeon, General
Hospital, Rangoon.
Lecturer in Surgery, Medical School, Rangoon.
Dr. V. S. John, M.B.B.S, (Rgn.),
L R.C.P. (Lond.), F.R.C.S.
(Eng)
Assistant to the Second Surgeon,
General Hospital, Rangoon.
Tutor in Surgery and Lecturer in Operative
Surgery, Medical School , Rangoon (Honorary).
Assumed charge from
the forenoon of 17th
June 1940.
Lt.-Col. H. S. Cormack, M.C.,
M.B., Ch.B. (Edin.), F.R.C.S.E.,
D.O. (Oxon.), I.M.S.
Ophthalmologist, General Hos-
pital, Rangoon.
Lecturer in Ophthalmology, Medical School, Ran-
goon (Honorary). Lecturer in Ophthalmology,
Medical College, Rangoon.
Transferred on the
afternoon of 14th
October 1940.
Major R, L. Reymond, B.A. (Oxon),
M.B., Ch.B. (Sydney), F.R.C.S.E,
D o .
Do.
Assumed charge on the
forenoon of 15th
October 1940.
Lt.-Col. M. L. Treston, F.R.C.O.G.,
F.R. C.S .(Eng.), M .R. C.S. ,
L.R.C.P. (Lond.), I.M.S.
Medical Superintendent, Dufferin
Hospital, Rangoon.
Lecturer in Obstetrics and Gynæcology, Medical
School, Rangoon. Professor of Obstetrics and
Gyræcology, University of Rangoon.
Lt.-Col. G. H. Fraser, M.B.,
Ch.B. (Edin.), D.P.M. (Eng.),
I.M.S.
Medical Superintendent, Mental
Hospital, Tadagale.
Lecturer in Mental Diseases, Medical School,
Rangoon. Lecturer in Mental Diseases, Medical
College, Rangoon.
Dr. S. K. Dey, L.D.Sc., D.E.D.P. Dentist, General Hospital, Ran-
goon (Part-time).
Lecturer in Dentistry, Medical School, Rangoon
(Honorary).
Dr. D. C. Vermani, M.R.C.S.
(Eng.) L.R.C.P. (Loud.), D. M.
R.E.
Radiologist, General Hospital,
Rangoon.
Lecturer in X'Ray work, Medical School, Rangoon
(Honorary).
APPENDICES.
1 3
A N N E X U R E I I .
List of Examiners.
Examinations.
Subjects.
Examiners.
September 1940.
March 1941.
(1)
(2)
(3)
(4)
Primary Examination
Chemistry
U Chit Thoung, M.Sc. (Lond.), D.I.C., A.R.C.S.,
F.C.S.
U Chit Thoung, M.Sc. (Lond.), D.I.C., A.R.C.S.,
F.C.S.
U Po Tha, M.Sc.
U Po Tha, M.Sc.
Physics
U Chit Thoung, M.Sc. (Lond.), D.I.C., A.R.C.S.,
F.C.S.
U Chit Thoung, M.Sc. (Lond.), D.I.C., A.R.C.S.,
F.C.S.
Mr. Pwa Yu Kin, B.Sc.
Mr. Paw Yu Kin, B.Sc.
Intermediate Examination Anatomy
Major G. M. Irvine, M.D. (Dub.), L.M. (Dub.),
F.R.C.S.E., I.M.S.
Major G. M. Irvine, M.D. (Dub.), L.M. (Dub.),
F.R.C.S.E., I.M.S.
Dr. J. W. Lusk, M.B., Ch.B. (Edin.) Dr. J. W. Lusk, M.B., Ch.B. (Edin.).
Physiology
Major C. F. J. Cropper, B.A. (Oxon), M.R.C.S.,
I.M.S.
Major C. F. J. Cropper, B.A. (Oxon.), M.R.C.S.
I.M.S.
Major H. Min Sein, M.B., M.R.C.P., I.M.S. Major H. Min Sein, M.B., M.R.C.P., I.M.S.
Materia Medica Dr. G. L. Chaudhuri, M.B. (Cal.), M.R.C P.E.,
F.R.F.P. & S. (Glas.), D.T.M. & H. (Edin.).
Dr. G. L. Chaudhuri, M.B. (Cal.), M.R.C.P.E.,
F.R.F.P. & S. (Glas.), D.T.M. & H. (Edin.)
Dr. U Maung E, M.R.C.P.E. D r . U M a u n g E , M . R . C . P . E .
Final Part I Examination Medical Jurispru-
dence.
Dr. Ba Than, M.B. (Cal.), F.R.C.S.E.
Dr. Ba Than, M.B. (Cal.), F.R.C.S.E.
Dr. A. Mobsby, M.B.B.S. (Rgn.)
Dr. Saw Be Graf, M.B.B.S. (Ran.).
Hygiene
Dr. K. T. Jungalwalla, L.M. & S. (Bom.),
F.R.F.P. & S. (Glas.), D.P.H., D.T.M. & H.
Dr. K. T. Jungalwalla, L.M. & S. (Bom.)
F.R.F.P. & S. (Glas.), D.P.H., D.T.M. & H.
Major T.J. Davidson, M.B., Ch.B. (Aberd.),
D.T.M. & H. (Eng.), D.P.H. (Aberd.), I.M.S.
Major T.J. Davidson, M.B., Ch.B. (Aberd.),
D.T.M. & H. (Eng.), D.P.H.(Aberd.), I.M.S.
Pathology
Lt.-Col. R.H. Malone, L.R.C.P. & S. (
Edin.),
M.D., D.P.H. (Mcgill.), I.M.S.
Lieut.-Col. R H. Malone, L.R.C.P. & S. (Edin.),
M.D., D.P.H. (Mcgill.), I.M.S.
Dr. P.G. Gollerkeri, M.D. (Bom.)
Dr. P.G. Gollerkeri, M.D. (Bom.).
Final Part II Examination Medicine
Lieut.-Col. C. de C. Martin, M.D., M.B. Ch.B.
(Edin.), I.M.S.
Lieut.-Col. C. de C. Martin, M.D., M.B., Ch.B.
(Edin), I.M.S.
Dr. M. L. Kundu, M.B. (Cal.), F.R.F.P. & S.,
(Glas.).
Dr. M. L. Kundu, M.B. (Cal.), F.R.F.P. & S.
(Glas.).
Surgery
Lieut.-Col. H. Aung Khin, M.B., Ch.B. (Edin.),
F.R.C.S.E., I.M.S.
Lieut.-Col. H. Aung Khin, M.B., Ch.B. (Edin.),
F.R.C.S.E., I.M.S.
Lieut.-Col. H, S. Cormack, M.C., M.B., Ch.B.
(Edin.), F.R.C.S.E., D.O. (Oxon.), I.M.S.
Major R L. Reymond, B.A. (Oxon.), M.B.,
Ch. B. (Sydney), F.R.C.S.E., I.M.S.
Dr. V. S. Hariharan, F.R.C.S. (Eng.)
Dr. V. S. Hariharan, F.R.C.S. (Eng.).
Obstetrics and
Gynæcology.
Lieut.-Col. M. L. Treston, F.R.C.O.G., F.R.C.S.
(Eng.), M.R.C.S., L.R.C.P. (Lond.), I.M.S.
Lieut.-Col. M.L. Treston, F.R.C.O.G., F.R.C.S.
(Eng.), M.R.C.S., L.R.C.P. (Lond.), I.M.S.
Dr, Ma Yin May, M.R.C.P., F.R.C.S.E.
Dr. Ma Yin May, M.R.C.P., F.R.C.S.E.
APPENDICES.
15
G.B.C.P.O.—No. 6, I.G.C.H., 9-8-41—235—III.
(NEW SERIES.)
No: 2.
SCIENTIFIC MEMOIRS
BY
OFFICERS OF THE MEDICAL AND SANITARY DEPARTMENTS
OF THE
GOVERNMENT OF INDIA.
MALARIA IN INDIA
BY
CAPTAIN S. P. JAMES, M.B. (LOND.), I.M.S.
(On Special Duty with the Royal Society's Commission on Malaria).
ISSUED UNDER THE AUTHORITY OF THE GOVERNMENT OF INDIA BY
THE SANITARY COMMISSIONER WITH THE GOVERNMENT
OF INDIA, SIMLA.
CALCUTTA :
OFFICE OF THE SUPERINTENDENT OF GOVERNMENT PRINTING, INDIA,
1902.
Price Rs. 1-8 or 2s. 3d.
x
No. 2.
(NEW SERIES.)
SCIENTIFIC MEMOIRS
BY
OFFICERS OF THE MEDICAL AND SANITARY DEPARTMENTS
OF THE
GOVERNMENT OF INDIA.
MALARIA IN INDIA
BY
CAPTAIN S. P. JAMES, M.B. (LOND.), I.M.S.
(On Special Duty with the Royal Society's Commission on Malaria).
ISSUED UNDER THE AUTHORITY OF THE GOVERNMENT OF INDIA BY
THE SANITARY COMMISSIONER WITH THE GOVERNMENT
OF INDIA, SIMLA.
CALCUTTA:
OFFICE OF THE SUPERINTENDENT OF GOVERNMENT PRINTING, INDIA.
1902.
Agents for the Sale of Books published by the Superintendent of Government
Printing, India, Calcutta.
IN ENGLAND.
E. A. ARNOLD, 37, Bedford Street, Strand, Lon
-don, W.C.
CONSTABLE & Co., 2, Whitehall Gardens, London,
S.W.
SAMPSON Low, MARSTON & CO., St. Dunstan's
House, Fetter Lane, London, E.C.
P. S. KING & SON, 2 & 4, Great Smith Street,
Westminster, London, S.W.
LUZAC & Co., 46, Great Russell Street, London,
W.C.
KEGAN PAUL, TRENCH, TRÜBNER & CO., Charing
Cross Road, London, W.C.
B. A. QUARITCH, 15, Piccadilly, London, W.
WILLIAMS and NORGATE, Oxford.
DEIGHTON BELL & CO., Cambridge.
ON THE CONTINENT.
R. FRIEDLÄNDER & SOHN, II, Carlstrasse, Berlin,
N.W.
OTTO HARRASSOWITZ, Leipzig.
KARL W. HIERESMANN, Leipzig.
ERNEST LEROUX, 28, Rue Bonaparte, Paris.
MARTINUS NIJHOFF, The Hague.
IN INDIA.
THACKER, SPINK & CO., Calcutta and Simla
.
NEWMAN & CO., Calcutta.
THACKER & CO., LD., Bombay.
D. B. TARAPORE VALA, SONS & CO., Bom
bay.
A. J. COMBRIDGE & CO., Bombay.
MRS. RADHABAI ATMARAM SAGOON, BOMBAY.
HIGGINBOTHAM & CO., Madras.
V. KALYANARAMA IYER & Co., Madras.
RAI SAHIB M. GULAB SINGH AND SONS, Mufid-I-Am
Press, Lahore.
SUPERINTENDENT, AMERICAN BAPTIST MISSION
PRESS, Rangoon.
CONTENTS.
PART I.
PAGE
Methods of Investigation . . . . 1
PART II .
CHAPTER I. Observations on anopheles mosquitoes and their larva . . . .27
" II. On the malarial infection of native children in India . . . . 59
" III. Observations on the causes which influence the prevalence of malaria
in different parts of India . . . . 73
" IV. The relation between enlarged spleens and malarial infection . . . . 85
" V. Note on the malarial parasites and fevers of India . . . . 95
" VI. Observations on birds . . . . 99
NOTE.
THE work recorded in this report includes the greater part of that done conjointly
by Dr. J . W. W. Stephens, Mr. S. R. Christophers, M.B., and myself, during the
time I was associated with them in India, as well as some of the work I have done
since their departure. It may happen that, as I have not yet seen their reports, my
conclusions may, in some cases, differ from those of Drs. Stephens and Christophers.
It should be noted, therefore, that only my own opinions are expressed in this report.
S. P. JAMES,
Captain, I. M. S.
MALARIA IN INDIA.
PART I.
METHODS OF INVESTIGATION.
I PROPOSE first to describe, under the following headings, some methods we
have employed in our investigations
:—
(1) Methods for the examination of the blood.
(2) Methods for the examination of the malaria parasite in mosquitoes.
(3) Methods for the investigation of malaria in hospitals and jails.
(4) Methods for the investigation of malaria among the general popula-
tion.
(5) Methods for the study of mosquitoes.
I.—The examination of the blood.
The diagnostic evidence of malarial infection which can be obtained from a
microscopic examination of the blood is as follows :
—
(a)
The detection of malaria parasites.
(b)
The detection of malarial pigment in the leucocytes.
(c)
The detection of a change in the proportion of the large mono-
nuclear leucocytes.
The two last are valuable when from any cause—such as the previous ad-
ministration of quinine—parasites cannot be found in the peripheral circulation.
For the detection of parasites, the blood may be examined in fresh prepara-
tions, or in dried and stained films.
When the object is to study carefully any individual case of malaria in a
hospital, it is necessary to examine both fresh and stained preparations of blood
taken at the same time.
As a rule, however,—and especially in cases where only one specimen of
blood can be obtained,—far more information is gained by the examination of
stained films than from wet preparations, and for routine work we have usually
employed this method.
In taking blood films for staining purposes the film of blood should be
spread on a glass slide with the surgical needle with which the finger has been
pricked. This method offers great advantages over any other, for not only
B
2
does it produce an extensive and evenly spread film of blood, but the ease
and rapidity with which a large number of specimens can be taken by this
method renders it the only practicable one for taking specimens of blood from
village children. During such operations the crowd and dust are usually
so great that an attempt to take specimens on cover-glasses or by any other
method could only end in failure.
A straight surgical needle, the eye of which has been previously removed
with a pair of forceps, should be used for this method of taking films. We
thus have a needle with a good point and a straight shaft. The finger is
pricked and a clean glass slide is lowered on to the drop of blood that exudes,
so that it touches the drop about half an inch from one end of the slide. Care
should be taken to allow the slide only to just touch the drop of blood—if it
touches the finger as well, dirt and numerous skin organisms will be transferred
in addition to the blood. The slide is then held between the finger and thumb
of the left hand, and the shaft of the needle (which is held by the point) is placed
crosswise on the slide over the drop of blood. (Fig. I.)
Fig. i.
A slight to and fro motion of the needle, across the slide assists the blood to
run along the under surface of the needle, and when this has occurred, it is drawn
evenly along the slide to the end, thus making a broad even film of blood. The
drop of blood taken should not be large enough to make the film cover the whole
slide, and a good film should end in a number of "tags" about an inch from the
end of the slide. (Fig. 2.)
Fig. 2.
The films taken in this way dry almost immediately in the air, but in the
damp heat of Southern India it is well to warm the slides over a spirit lamp before
taking specimens of blood, lest the moisture on them or on the patient's finger
should cause the formation of vacuoles in the blood corpuscles. When dry, the
3
films are fixed by immersion from ten minutes to half an hour in absolute
alcohol. For this and for staining purposes the glass stain-pots shown in Fig. 3
A Gr a p h i c a p p e a r s h e r e s e e F i g . 3 . o f p a g e 3
will be found very useful. A large number of slides can be fixed in one of these pots
at the same time ; but before placing each slide in the alcohol, a number by which
it will be known should be written upon it with Indian ink or a "glass pencil."
For staining blood films we have usually employed either alcoholic hæma-
tin or Romanowsky's stain, and other stains than these are seldom necessary.
The alcoholic hæmatin stain possesses the advantages of being very
easily worked, of being permanent, and of showing up the pigment in malaria
parasites better than Romanowsky's stain. With a little practice, however,
very beautiful results can be obtained by Romanowsky's method, and as, in a
slide stained by this method, it is almost impossible to overlook even the smallest
ring forms, it is to be recommended even for routine work.
The alcoholic hæmatin stain is made as follows :*—
Hæmatein purissimus
2 grammes.
Alcohol ( 90 %)
50 C. C.
Alum
50 grammes.
Distilled water
1,000 C. C.
The fixed and dried films are left in this solution for from ten to twenty
minutes or longer, until the blood film has a faint brown hue. They are then
washed in water, allowed to dry in the air, and examined with the oil-immer-
sion lens without applying a cover-glass. The parasites show clearly against
the grey brown colour of the red cells.
Romanowsky's stain is made as follows :—
Stock solution, A :—
Pure medicinal methylene blue (Grübler)
1 gramme.
Pure sodium carbonate
1/ 2 gr amme.
Distilled water
100 C. C.
Grind up the methylene blue in a pestle and mortar and add it gradually to
the water. When the solution has been made, add the sodium carbonate.
* Reports to the Malaria Committee of the Royal Society, 3rd Series, Stephens and Christophers
" The Malarial Fevers of British Central Africa."
B 2
5
and the blood platelets are correctly stained, for the parasites will be found to
show up quite plainly in the bluish corpuscles.
A useful property of Romanowsky's stain is its power of causing the red
cells which have been invaded by simple Tertian parasites to become stippled
with red dots, thus making cells containing these parasites very easily recog-
nisable. This stippling, which is probably the result of degeneration in the
corpuscle, does not, of course, occur in every corpuscle that is invaded by
a simple Tertian parasite, but in every correctly stained slide of simple Tertian
parasites, there will be a large proportion of stippled cells, and on the whole,
it is a very characteristic sign. A pseudo-stippling sometimes occurs in blood
corpuscles invaded with malignant Tertian parasites, but this pseudo-stippling
is readily distinguished from the characteristic appearance presented by
corpuscles invaded with the simple Tertian parasite.
After a slide has been examined the oil should be removed with a few
drops of xylol : the slide can then be wrapped in paper and kept indefinitely.
It is somewhat difficult to prepare good specimens of flagella bodies, and
it is usually preferable to observe them in the fresh state. In cases, however,
where flagella bodies are fairly numerous, I have found the following method
give good results.
A moist chamber is first made by cutting a round hole the size of a large cover
slip in a thick piece of blotting-paper, and applying this over the cell of a hollow
ground glass slide. The blotting-paper is well moistened with water. The
finger should be pricked and a large drop of blood squeezed out. During this
operation it is well to breathe continuously on the drop of blood as it exudes, and
while it is resting on the finger. The drop of blood is then transferred to the
middle of a clean glass slide and inverted over the moist chamber cell : the
blood should not be spread out on the slide but should remain as a hanging drop.
A number of similar hanging drops of blood are prepared and placed in
moist chambers. At varying periods of time after their preparation,—from five
minutes to half an hour or more,—the slides should be removed from the moist
chambers, and thin films made from the drops of blood on other slides, in the
manner before described for the preparation of ordinary blood films.
These films are dried in the air, fixed, and stained by Romanowsky's
method.
With these thin films it is of course unnecessary to dissolve out the hæmo-
globin of the red blood corpuscles in order to see the flagella bodies.
It is not necessary to describe the method of taking fresh specimens of
blood. Absolute cleanliness of slides and cover-glasses is essential, and it may
be noted that the best way to put the final cleaning touches on to slides is to
heat them over a spirit lamp. As a rule it is preferable not to ring the cover-
glasses of fresh specimens of blood with vaseline.
6
Fresh specimens should be examined with the oil-immersion lens and with
carefully arranged light : if too much light passes through the specimens the
parasites are difficult to see.
To those who are unfamiliar with malaria parasites the examination of
fresh specimens of blood is full of pitfalls. Anything which seems to have the
appearance of a parasite, but which is not actually inside a red blood corpuscle,
and especially such things as "free pigment," "free spores" (unless the
latter are actually seen breaking away from a segmenting parasite), should be
disregarded.
In cases where there is any doubt and especially in cases where only
unpigmented forms appear to be present, it is better to take films and stain them
by Romanowsky's method.
In stained films, unless scrupulous attention has been paid to the cleanliness
of the patient's finger, we should be on the watch for skin parasites, which often
present a superficial resemblance to malaria parasites.
It is unnecessary, however, to enumerate all the things that may be mistaken
for malaria parasites, and experience has shown that no advantage is gained by
doing so : * it is sufficient to say that the malaria parasite is so definite an organ-
ism that anything about which, after careful examination, it is possible to have
the least doubt is almost certainly not a parasite.
The detection of pigmented leucocytes.—It not infrequently happens in
cases of malarial fever, and especially in cases where the patient has been taking
quinine, that parasites are absent from the peripheral circulation. In such cases
it has been pointed out by Stephens and Christophers that the diagnostic value of
an examination for pigmented leucocytes and a differential count of the leucocytes
is very great.
For both these examinations stained films should be employed. In an
examination for the detection of pigment in leucocytes, special attention should
be paid to the large mononuclear elements, for it is in these that the characteris-
tic appearances are chiefly found, The pigment may vary from a number of
large blocks or clumps to one or two fine spicules only, which may be difficult
to detect, but which, when recognised, are as absolutely diagnostic of recent
malarial infection as the presence of parasites. A common appearance is that of
one or two large blocks of pigment and a number of fine grains or spicules scat-
tered through the cell. Appearances as of pigment in any other elements
* A great deal of very careful practice is necessary to become an adept at finding parasites, and I have
repeatedly seen men who could at once recognise a parasite when it was pointed out to them, spend an hour
or more over a film containing a fair number of parasites without being able to find one for themselves.
Even the Burman prisoners at Nagpur, who were well practised in examining slides, when examining
malignant Tertian cases, on several occasions passed over very obvious simple Tertian parasites which were
present in the films as well. On the other hand, it is even more common for men to think they see para
- s i t e s i n a l m o s t e v e r y f i e l d w h e n n o n e a r e p r e s e n t i n t h e f i l m a ta
l l .
7
than the large mononuclear cells are, in the absence of parasites, of less diag-
nostic value.
The differential count of leucocytes.— It has been shown that in malarial
fevers a variation occurs in the relative proportions of the leucocytes, this varia-
tion consisting chiefly in an increase in the large mononuclear cells accompanied
by a decrease in the polynuclear and small mononuclear cells. As a diagnostic
sign of recent malarial infection this increase in the proportion of the large
mononuclear cells is of especial value in cases where no parasites can be found
in the peripheral circulation, e.g., where quinine has been taken.
To make this differential count of the leucocytes is a somewhat difficult task
and one requiring much time and patience: it is essential also to have made a
good many counts of normal blood slides before attempting a differential count
of malarial blood films.
For making the count, a mechanical stage and well-spread even films
prepared by the method before described are necessary. The films may be
stained by Romanowsky's method or with Ehrlich's triple stain. In a well-spread
film nearly all the leucocytes will be found distributed along the edges and in
the tags at the end of the film. If these parts of the slide are examined first,
practically all the leucocytes in the film can be counted. One thousand
leucocytes in all should be counted and, unless the observer is very practised in
making blood counts, results obtained from counts of less than this number
cannot be relied upon.
In making the count, the following forms should be noted separately:-
(1) Large mononuclear leucocytes.
(2) "Transi t i onal " forms of l eucocyt es.
(3) Small mononuclear leucocytes (lymphocytes).
(4) Pol ymorphonucl ear l eucocyt es.
( 5 ) E o s i n o p h i l e l e u c o c y t e s .
The chief difficulty is in deciding definitely the form of leucocyte to be
included under the term large mononuclear, and on this decision will depend
the accuracy or the reverse of the results obtained.
The large mononuclear leucocytes are sharply distinguished from the
lymphocytes.* They are large cells about twice to three times the size of the
red blood corpuscles. They possess a large oval nucleus as a rule eccentrically
situated, and a relatively abundant protoplasm which is free from granulations
and stains very faintly.
In normal blood of natives from 7 to 10 per cent. of all the leucocytes are of
the large mononuclear variety.
"Transitional" forms, which should not, as a rule, be counted along with
* " Histology of the Blood," by Ehrlich and Lazarus, translated by W. Myers. Cambridge University
Press.