Ronald Ross Nobel Lecture

72

   1 9 0 2   R .R OS S

information on the subject. Once more I had to depend on myself; and I there-

fore took special note of the dappled-winged mosquitoes found near my la-

boratory. No less than four species were detected - a large brown species, a

large greenish one (with which the experiments just described were made), a

small black one, and a small brown one. The first was named later by Giles

from specimens brought to England by me, and was called by him Anopheles

rossi; 

and from the studies of Stephens and Christophers made in Calcutta

some years subsequently it is almost certain that the second species was A. fu-

liginosus.

Numerous specimens of Proteosoma in grey mosquitoes were sent to Man-

son on the 30th March.

By the middle of April I had overworked myself, and was obliged to ask for

ten days’ leave to the Himalayan hill-station Darjeeling, where I hoped for

time to write my report in a cool climate. I had heard also of several intensely

malarious spots at the foot of the Darjeeling mountains, and hoped to be able

to carry on there the studies on human malaria which were debarred in Cal-

cutta and at the same time to continue my work on avain malaria. I therefore

left Calcutta on the 17th April.

16. The Darjeeling Terai (April-June, 1898). Efforts to obtain assistance. 

The re-

sults with Proteosoma were obviously so important that it was necessary to give

them to the world at once, in the hope that many observers would now be

easily able to follow the work, and also that I might obtain assistance in con-

sequence of my success. Consequently I devoted my time at Darjeeling to

writing a report to my chief, the Director General of the Indian Medical Ser-

vice, on my latest work. The report begins with a brief statement of my first

discovery of the pigmented cells,* followed by a list of the experiments, both

positive and negative, which I had made with a view to infecting mosquitoes

with human malaria. Then comes a detailed account of experiments and posi-

tive results with Proteosoma, followed by a minute description of the neces-

sary technique, and of the appearance, position, and development of the pig-

mented cells. Next I discuss several points, including the bearing of MacCal-

lum’s work on mine. As I had brought my microscope and some of my speci-

mens with me, I was able to add to the report large plates giving drawings of

the pigmented cells up to the stage to which they had as yet been traced.** The

work was, however, hurriedly executed, as I had only a few days in which to

* In the twelfth line the word "ordinary" is a slip of the pen for "other".

** These plates are reproduced at the end of this publication.

---

    R E S E A R C H E S   O N   M A L A R I A

73

write it. The pigmented cells are called in it "proteosoma-coccidia", a term

which has been criticized. I thought at that time that the parasites of malaria

really belong to the Coccidiidae, the early stages of their life being passed in

man and birds, and the later stages (to which the name Coccidia might more

appropriately be attached) in the mosquito; just as the early and later stages of

the sexual forms of C. oviforme occur respectively in the bile ducts and the in-

testine of the rabbit. At the end of the report a description of the grey and

brindled mosquitoes with drawings is furnished by Mr. G. C. Dudgeon, a

gentleman who was acquainted with entomology; and the report concludes

Fig. 3. From paper by Manson, British Medical Journal, 18th June, 1898, p. 1577. (After Ross’s

drawings.)

---

74

    1 9 0 2   R . R O S S

with the words, "These observations prove the mosquito theory of malaria as

expounded by Dr. Patrick Manson..."

The report after some delay, was dated 21st May, and was despatched at

once, with an urgent request that it might be published as soon as possible. To

my surprise I was informed that publication was not allowed without the per-

mission of the Secretary of State for India. This meant writing to England and

several months delay; but the report was printed very soon and numerous

copies were sent at the end of June to Manson for private circulation among

persons interested in malaria. In the meantime my success had been described

in detail both to Laveran and Manson in letters dated 22nd April - the letters

being accompanied by a series of seventeen more preparations; and, as my

results could not be published by myself, I now asked Manson to publish them

for me.

On the 18th June Manson published an able paper on the subject. The article

commences with a resumé of my orginal discovery of pigmented cells in dap-

pled-winged mosquitoes fed on a human patient with malaria, and gives the

references to my papers describing the observation

41

. It goes on to describe the

new results with Proteosoma; giving drawings of the pigmented cells up to the

sixth day of development, and a diagram showing the connection between

MacCallum’s observation and my own; and it concludes with letters from

Nuttall and Laveran accepting my results. Laveran said, "It appears to me to

be undoubted that the elements discovered by Dr. R. Ross in the stomach of

mosquitoes fed on the blood of birds, the subjects of haemosporidiosis, are

really parasites, and that these parasites represent one of the phases of the evolu-

tion of the haematozoa... I have shown the preparations to M. Metchnikoff,

who shares my opinion".*

This paper drew general attention to my work, to which previously little

credence had been attached; and, as many of my preparations had been sent to

England and France, not only were those competent to form an opinion en-

abled to judge of the truth of my statements, but those who wished to follow

my steps were now easily able to do so. In fact a most amusing comedy now

commenced, in which we witnessed the hasty efforts of those who had been

sceptics, not only to follow my steps but to persuade the world that their la-

bours were original. During several years since that date every observation of

mine has been independently discovered by various writers.

Recognizing the vast significance of these preliminary results with Proteo-

* Owing to a misapprehension, this paper erroneously states that Halteridium also had

been cultivated.

---