SIXTH ANNUAL REPORT. Ill 



by next year. That is the gastro-enteritis produced by the 

 presence of foreign bodies in the stomach. These have been 

 given the animals by mischievous or thoughtless visitors. Three 

 valuable specimens have died from this cause alone during the 

 past year. One, an expensive Japanese bear, had been fed 

 peach-stones in such quantity as to effectively block the pylorus, 

 producing an extreme acute gastritis, with finally complete 

 pyloric stenosis. Similarly, one of the deer had been given leaf- 

 lead in such an amount as to set up a fatal gastro-enteritis. Di- 

 rector Hornaday has taken stringent measures to stop this abuse, 

 and he should receive the assistance in this work not only of 

 the members of the Zoological Society, but also the help and 

 co-operation of every animal lover. The idea is all too prevalent 

 among the public that animals can " eat anything." 



DYSENTERY AMONG THE PRIMATES. 



Dr. Miller has dealt quite extensively in his report with the 

 epidemic of dysentery which occurred among the orangs, and 

 which also afifected the chimpanzee, with the result that all but 

 one of these animals died. 



Pathologically, this epidemic has been of great scientific and 

 practical interest, inasmuch as we have been able to identify the 

 cause of the disease, and this knowledge has enabled us, thus far 

 at least, to save one member of the orang family. 



The etiological factor of this epidemic was the Balantidium coJi 

 (Paramcccium coli), a parasite belonging to the order Hetero- 

 tricha. 



This organism was discovered by Malmsden in 1857, in the 

 mucous discharges of a patient who suffered from a persistent 

 diarrhoea following cholera. It is an oval body about four to 

 seven times the diameter of the human red blood-cell. It is 

 completely covered by cilia, arranged in parallel rows. An ec- 

 tosarc and endosarc are usually clearly shown. The mouth is 

 funnel-shaped, much like that of the ordinary paramoecium, and 

 is surrounded by a row of cilia which are larger than those over 

 the organism. There is also a small anal orifice at the posterior 

 extremity of the oval. The paranucleus is bean-shaped, and re- 

 acts diffusely to chromatic stains. The cytoplasm is granular, 

 and contains two large vacuoles; it often incloses bacteria, red 

 blood-cells, small granules of dirt, fat, or other material taken 

 up from the medium surrounding the parasite. 



