18 THE SOCIETY FOE THE PEESEEVATION OF 



fowls, creeping under their wings to bite the poorly protected 

 parts of the skin. ' The writers in question further remark that : * A 

 second possible source of food supply is furnished by the aquatic 

 animals of the lake shore, such as the hippopotamus, the otter, the 

 crocodile, and the python ' ; and they state that they ' have definite 

 evidence that the fly feeds on the hippopotamus and on the croco- 

 dile. ' It was also found that * flies in captivity sucked the blood 

 of lizards, chameleons, and snakes very freely.' ^ The statement 

 that the crocodile contributes to the support of Glossina palpalis 

 has within the last few months been confirmed by Professor Koch, 

 who, as the result of an eighteen months' sojourn on another 

 desolate island in the Sesse group, is reported to have declared 

 that : ' The blood of crocodiles forms the chief nourishment of the 

 Glossina, which sucks the blood between the plates of the animal's 

 hide. ' ^ Further evidence as to this indirect connection between 

 Crocodilus niloticus and sleeping sickness will doubtless be forth- 

 coming in Professor Koch's detailed report on his recent investi- 

 gations, w^iich has not yet been published. In the meantime 

 information has been received from a private source to the effect 

 that, while on Lake Victoria, the distinguished German investi- 

 gator examined the contents of the stomachs of large numbers of 

 wild-caught Glossina palpalis, with the result that he found that 

 in no less than 90 per cent, of the cases they consisted of crocodile 

 hlood. It remains to be proved how far this finding holds good for 

 other parts of Africa in which the sleeping sickness tsetse-fly 

 occurs; but at least it may be said that there is nothing in the 

 present-day distribution of the crocodile to prevent it being 

 generally true, while owing to the specially close association of 

 Glossina palpalis with water and the well-known habit of croco- 

 diles of basking on land for hours at a time, these reptiles would 

 seem eminently adapted by nature to provide sustenance for the 



fly- 



Be this as it may, the result of all observations hitherto made 

 is to show that in other parts of Africa big game is no more charge- 

 able with being the chief support of Glossina palpalis than on the 

 shores of Lake Victoria and its islands. In 1903 it was discovered 

 by Mr. W. Y. V\^yndham that this species of tsetse occurs all 

 round Lake Albert, in Uganda; yet, writing from Wadelai, on 

 November 2, 1903, to Dr. Nabarro at Entebbe, Mr. Wyndham 

 remarked : * The fly cannot depend for its existence upon game, 

 as in most of the places in which I found it there was none or next 

 to none.' Again, Dr. J. L. Todd, a member of the Expedition of 

 the Liverpool School of Tropical Medicine to the Congo, 1903-5, 

 writing of the results of nearly two years' experience in the Congo 

 Free State, after observing that on one occasion at Ijokandu, on 

 the Upper Congo, two or three Glossina palpalis followed two 



1 Minchin, Gray, and Tulloch, loo. cit. pp. 130, 131. 

 3 The Tinies, November 4, 1907, 



