332 BR. W. TORKE ON 



relationship of different organisms in nature was very complex, 

 and a sudden change brought about in the conditions might have 

 results altogether different to what was anticipated originally. 

 Dr. Yorke had argued, it seemed to him, as if the distribvition 

 and occurrence of tsetse-flies were fixed and immutable, and 

 had denied that there was any danger of their migrating 

 towards human habitations if the big game, their natural source 

 of food in the bush, were destroyed. Prof. Minchin found it 

 difiicult to believe, however, that if the tsetses in the bush were 

 deprived of their food, they Avould sit down and die of starvation ; 

 he thought it far more probable that the flies would migrate in 

 search of food, which they v/ould find in human beings and the 

 cattle suri'ounding their habitations. [Dr. Yorke maintained 

 that the shelter of the bush was nece^s^ry for the flies; but such 

 shelter might be found on cultivated land, especially in the 

 banana-plantations which often surrounded native hvits or 

 villages.] 



Considering the question, therefore, purely from a utilitarian 

 point of view, Prof. Minchin thought it within tlie bounds of 

 possibility, to say the least, that the wholesale destruction of the 

 big game might lead to a condition of things more dangerous and 

 disastrous than that existing at present. He urged that such 

 measures should be nndertaken, at first experimentally, on a small 

 scale and in a resti-icted area,, in order that accurate knowledge 

 might be obtained of the effects produced b}^ the elimination of 

 the wild ungulates before destroying them wholesale. 



Letter from The Hon. L. WALTER ROTHSCHILD, 

 D.Sc, F.R.S., F.Z.S. 



Dear Dr. Chalmers Mitchell, 



I am extremely sorry that, as I leave for Monaco on the 

 18th, I cannot attend the meeting. But I trust you will read 

 this letter at the meeting. Dr. Yorke suggests the extermination 

 or partial extermination of the ruminants and large game animals. 

 I wish to protest against this most emphatically on zoological and 

 ethical grounds. However, in order to prove to the utilitarians 

 the absolute uselessness of this proceeding, 1 should like to point 

 out that the extermination of the game animals in any large area 

 would be a task of several years' duration, and the following would 

 take place. As year by year the large animals grew scarcer, the 

 tsetse-flies Gloseina palpalis and morsitans, which are the means 

 of spreading Sleeping Sickness in men and N'gana in animals, 

 would be driven to bite monkeys, carnivoia, i-ats, mice, and the 

 numerous small animals of those regions ; these would be infected 

 and the trypanosomes of the disease would gaily survive. This 

 would not only mean the continuance of the disease in its present 

 degree, but would cause a sharp increase of both diseases. The 

 reason for this increase, to my mind, would be very evident, for 

 at present, owing to the abundance of large game animals, the 



