MONKEYS 131 



taught the difference in appearance between the eggs of 

 crocodiles and fowls ! 



But perhaps the lecturer was a humorist ? . . . 



Monkeys. 



One species of monkey, a Cercopithecus, lives on the 

 islands, but only on the largest : they were found on 

 Kome, Damba, Wema and Yempata out of those that 

 were visited in the group lying off the north shore of the 

 lake, and on Bugalla and the larger isles of the Sesse 

 groujD. A very curious fact is their presence on the Isle 

 of Nkosi, which is the southernmost of all the Sesse isles, 

 quite small and in a very isolated and exposed position ; 

 when I visited this islet in 1913 I distinctly heard a 

 monkey's voice, though he was not visible (see p. 92). 

 The species is of a common type : greenish grey in 

 colour, with black face and a white band across the fore- 

 head. It has been of very great service in the investigation 

 of Sleeping Sickness, since the Trypanosomes which cause 

 that disease are also pathogenic to the monkey, which 

 can thus be used as a test for infected flies. Hence I had 

 one with me on the islands for this purpose, and also 

 two others as pets. The " official " one was dubbed 

 Tommy, and, of course, had to be kept tied up, as also 

 was the older of the two pets, named Wee Man. The 

 third, PufRn, was a mere baby, and had not yet become 

 sufficiently mischievous for it to be necessary to tie him 

 up. When I first had Wee Man he was also allowed to 

 run loose, but became so mischievous that when I moved 

 to Bugalla he was tied up. 



Being in very constant association with them, one soon 

 became thoroughly familiar with their behaviour, their 

 moods, facial expressions and language, and soon found 

 oneself able to distinguish the meanings of their various 

 utterances. 



No less than fourteen sounds are used, although some 



