154 



WALTER JONES 



o ( 



NH C=O 



l'-XH\ + H 2 + O 



\ c=o 



NH C NH/ 



L'ric Ac-id 



NH 0= 



\ 



H 2 N\ 



NH CH NH/ 



allantoine 



c=o 



co. 



Thus tho pnrino fermentation is effected by four independent physio- 

 logical agents. 



1. guamse, 2. adenase, 3. xanthine-oxidase, 4. uricase. 

 Three of these lead up to the formation of uric acid and the fourth brings 



about its destruction. 



Nucleic Acid 



guanme 



adenine 



; i 



allantoine uric acid xanthine hypoxanthine 



A study of the localization of these ferments discloses interesting and 

 important matter. 



THE DISTRIBUTION OF THE PURINE FERMENTS 



1. With very rare exceptions, the four ferments of the purine fer- 

 mentation are not present in any one tissue. The distribution character- 

 izes the tissue and the species. This variation of the distribution with 

 species, as well as the independent existence of guanase, adenase and xan- 

 thine-oxidase is shown by an examination of the livers of four different 

 species. (Jones and Austrian (a) (1906).) Ox liver forms uric acid from 

 both amino-purines, pig's liver from only one (adenine), rabbit's liver only 



