186 Zoologica: N. Y. Zoological Society. [I; 9 



normal salt solution, and quinine bisulphate were administered 

 without appreciable result. 



The disease progressed steadily, the animals dying within a 

 few days of each other. The post-mortem examinations were made 

 by Dr. Brooks, who was able to identify the cause of the disease to be 

 the invasion of the intestinal mucosae by the Balantidium coli {Para- 

 mcecium coli), a parasite belonging to the Order Heterotricha. This 

 organism was discovered by Molmsden in 1857, in the mucus 

 discharges of a patient who suffered from a persistent diarrhoea 

 following cholera. The Balantidium is an oval body, about six or 

 seven times the diameter of a human red-blood cell; is quite actively 

 motile, but soon ceases its movements if exposed to cold, acids, or 

 disinfectants. 



The lesions produced by the Balantidium coli are principally 

 confined to the large intestine, where in the case of the orangs, the 

 entire mucous membrane of the colon was transformed into an 

 almost continuous succession of large irregular ulcers. Microscopic 

 examination of sections of these ulcers showed myriads of parasites 

 burrowing beneath the mucous membrane, even along the lymphatic 

 channels of the muscular coat and in places as far down as the 

 peritoneum. 



Just how this deadly protozoan first reached the apes remained 

 for several months a complete mystery. A diligent microscopic 

 search of the faeces of all possible sources of immigrat on was finally 

 rewarded by the startling discovery that the faeces of the giant 

 tortoises from the Galapagos Islands, exhibited during the summer 

 in a yard surrounding the open-air cages of the orang-utans, were 

 swarming with Balantidii but which had not caused these reptiles 

 the least inconvenience. 



Owing to the danger of this parasite to the higher apes, and the 

 unsatisfactory treatment, it is important that an early diagnosis 

 should be made in suspected cases of dysentery in apes, in order that 

 strict isolation of infected ones should be carried out. An easy and 

 positive examination may be made by microscopic examination of the 

 fsecal discharges of infected animals when the actively motile Balan- 

 tidii are to be seen. 



