Purine Enzymes of Anthropoids and Marsupials. 153 



Although these mice did not contain any other protozoan 

 parasites in the intestine, I hesitate to connect positively the small 

 ameboid and schizogony forms with the newly introduced Sarco- 

 sporidian "spore" until further study actually demonstrates the 

 transition. 



A complete account of the work will appear in the Arch. d. 

 Zool. exper. et gen., T. 52, 1914. 



95 (912) 



The purine enzymes of the anthropoids and marsupials. 

 By H. Gideon Wells and George T. Caldwell. 



[From the Otho S. A. Sprague Memorial Institute and the University 



of Chicago.] 



Previous studies have shown that the human organism con- 

 tains no enzymes which will destroy uric acid in vitro, in which 

 respect man differs from all other mammals hitherto investigated. 

 This corresponds with the repeated observations, especially of 

 Wiechowski, that man alone of all domestic mammals excretes 

 uric acid rather than allantoin as the chief end product of purine 

 metabolism. These facts have been especially emphasized of 

 late by Andrew Hunter. One of us found that even the monkey 

 has no demonstrable uricolytic enzymes in its tissues. Wiechowski 

 made the interesting observation that the chimpanzee, like man, 

 excretes only uric acid and little or no allantoin, while Hunter 

 and Givens reported that monkeys resembled the other mammals 

 in excreting chiefly allantoin, corresponding with our observations 

 on the purine enzymes of the monkey. We have recently, through 

 the kindness of Dr. W. T. Hornaday of the New York Zoological 

 Society, come into possession of two fresh bodies of anthropoids — 

 a male chimpanzee and a female orang-utan. Examination of 

 their tissues shows that, like man, they do not possess the uricolytic 

 enzyme, uricase, demonstrable in vitro. They also resemble adult 

 man in having guanase but no demonstrable adenase. Hence 

 it seems that the anthropoids stand with men in constituting, 

 in respect to uricolytic power, an exception to all other known 

 mammals; the monkeys resemble the other lower mammals in 



