258 EVOLUTION AND DISEASE. 
racters, for these deposits consist of a crystalline sub- 
stance resembling guanin and urate of soda, and respond- 
ing to the murexide test. Guanin and urate of soda are 
closely allied bodies, and as far as I can ascertain it is no 
easy task to decide between them. Until the subject 
has been more thoroughly investigated it will remain 
uncertain whether the nodular lesions of parrots and 
other birds are really of the same nature as gout in man, 
or allied to guanin gout of the hog, and it is very 
Fic. 125.—The feet of a Parrot with supposed gouty nodules. 
probable that some case of supposed uratic gout in man 
may be guanin gout. 
This confounding of avian and human gout, and 
trichinosis with the guanin gout of the hog, is easy to com- 
prehend, as it requires chemical cunning to complete the 
identity, but we must remember that true gout was 
formerly, and is now, often confounded with a disease 
of the articular ends of bone, which, though often referred 
to as rheumatic gout, has no relation with gout, except 
that both diseases are distinguished by nodules on the 
