11
PUBLIC RECORD OFFICE
Reference -
། ། ། ། ་། ། wminum C.O. 885
22 PUBLIC RECORD OFFICE, LONDON
ALLY WITHOUT PERMISSION OF THE BE REPRODUCED PHOTOGRAPHIC COPYRIGHT PHOTOGRAPH-NOT TQ
10
8. Much of this, however, is beside the point. We know now, as Dr. Prentice says, that game is a natural reservoir of the human and other trypanosomes in We know also Rhodesia and Nyasaland, and probably the principal reservoir. that the human trypanosome in those regions is conveyed by the widely prevalent fly, Glossina morsitans, which feeds on both man and game. Dr. Prentice believes that the removal of the game from tsetse arcas would remove sleeping sickness and trypanosome infections of domestic animals. Others think that even were it possible successfully to attack the game over such large stretches of country-and many competent persons doubt it--such an abrupt interference with nature might have results, both immediate and remote, other than those intended.
9. For my part, I agree with the opinion of Dr. Yorke, published in the paper I have quoted, that a large experiment scientifically conducted is at first essential, and I doubt whether it can be made a success without some means, such as a fence, of keeping wild animals from straying into the area selected.
I hope, therefore, that it will be possible without further delay to put in hand some form of Sir David Bruce's scheme. Paper discussions are time-consuming, and no argument will carry conviction to persons who are threatened, in themselves or their stock, with trypanosome infections.
10. Meantime a serious effort should be made by expert entomologists of experience in dealing with insect pests to devise in the field some means of attacking the fly directly; for if the fly could be greatly reduced in numbers and kept down the trypanosome problem would resolve itself.
7893
SIR,
I have, &c.,
ARTHUR G. BAGSHAWE,
Director
No. 12.
THE SECRETARY OF STATE to THE GOVERNORS.
[Answered by Nos. 24, 33, and 38.]
(Gold Coast. No. 148.)
(Sierra Leone. No. 92.) (Gambia. No. 55.)
Downing Street, 11 March, 1913.
WITH reference to the correspondence ending with [Lord Elgin's despatch of the 14th of May, 1907*] [Sir L. Probyn's despatch, No. 164, of the 21st April, 19091][Sir G. Denton's despatch of the 19th (1st) August, 19074], I have the honour to request that you will consider the question whether it is not now desirable to do something in the direction of forming reserves or sanctuaries for the wild fauna of the Colony under your government.
2. I would explain that what I have in view is not so much the protection of what is usually called game in the interest of sportsmen as the preservation of wild life of all kinds, including birds and rodents, from the danger of extinction, in the interest of science and of all who are interested in wild life.
3. I have noted with regret that certain species of animals have become extinct in recent years in various parts of the world, and I am anxious to prevent a loss of this kind, which is by its very nature irreparable, occurring in territories under British control.
4. I realise, of course, that protection cannot be given to animals which are noxious to mankind, either directly or by harbouring diseases communicable to man, or even to those which are seriously inimical to agricultural produce; but, within these limits, I trust that something may be done in the direction which I have indicated.
I have, &c.,
L.. HARCOURT.
9811
No. 13.
MEMORANDUM.
SLEEPING SICKNESS AND BIG GAME.
"
I agree with much that Dr. Yorke says in the lecture delivered before the Liver- pool Chamber of Commerce on "Sleeping Sickness and Big Game." I do not con- sider, however, that a sufficient variety or sufficient numbers of the wild animals of Rhodesia have been examined to enable one to say that antelope are the sole reservoir. of the trypanosomes of man and domestic stock. I have carefully analysed the figures given by Kinghorn and Yorke, and find that their tables include 177 ante- lopes and 74 other animals. In the case of the other animals examined (rats, mice, and monkeys) no details are given. Apart from the fact that T. rhodesiense was found in a warthog, it is obvious that, had a greater number of mammals not included in the term "
big game
been examined, disease-producing trypanosomes might have been found in some. I append the figures, classified under the headings antelope and non-antelope; it will be noticed that in the case of many species very few individuals were examined and that inoculation of their blood into susceptible animals was in many instances not made, so that the results obtained are untrust- worthy. I have not yet seen Sir David Bruce's paper on this subject, read before the Royal Society on March 6th, and do not know whether or not the work of the Commission in Nyasaland confirms that of Kinghorn and Yorke. Bruce found disease-bearing trypanosomes in Zululand in a hyæna. I think it is becoming evident, however, that under present conditions antelope form the chief reservoir.
I am specially interested in the comments on Mr. Harcourt's speech in the House of Commons because this was partly based on a memorandum of my own. Re domestic animals, it is true that all the evidence goes to show that domestic animals do not long survive infection with T. rhodesiense; no case of recovery has yet been recorded. I do not think we can yet say that recovery never occurs, but I must concede that in Rhodesia and Nyasaland domestic animals appear to be negligible as reservoirs. This conclusion is based on what we have learned since the date of my memorandum. With T. gambiense the case is otherwise, as also with some of the trypanosomes of domestic animals.
I do not agree that tsetse fly do not invade the clearings in and round native villages to any great extent, and therefore man is only attacked when he goes into the bush, but this is not a point of great importance, as the pursuits of the native take him frequently into the bush. (The clearings here named are such as the native makes for his own convenience.)
It may be the case that with the removal of the game trypanosome diseases of man and domestic animals would disappear, but this is by no means certain, for the reasons given in the first paragraph. The large experiment advised by Dr. Yorke is what is necessary to give us further information. If after the removal of the big game from the selected area the tsetse were still found to be infected with pathogenic trypanosomes we should know that we had to look for another reservoir, either one which was additional to the big game or one which had taken its place. The experi- ment, in my opinion, is essential, but every effort must be made to eliminate factors which would vitiate the conclusions to be drawn from it.
It will take time and I would advocate in the interim sustained efforts to devise methods of reducing the fly's numbers. Such good naturalists as Professor Newstead, Mr. Austen, and Colonel Alcock believe that this line is well worth following. Some study has been made of the bionomics of tsetse, but no experiments have yet been devised with the direct object of reducing the numbers of G. morsitans or other tsetse by men who have had experience in dealing with other insect pests. If Newstead had been long enough in Nyasaland he would doubtless have undertaken such experiments.
13 March, 1913.
ARTHUR G. BAGSHAWE.
• No. 21 in [C1. 1172).
† 15277: not printed.
‡ No. 32 in [Cd. 4472].
}