154 WALTER JONES 



/ I 



O^C NH\ + H.O + O 



\ II c=o 



XII C NH/ 



L'ric Acid 



XII CO 



/ I 



= 0-C H 2 N\ 



\ c=0 + CO, 



NH CH Nil/ 



allautpine 



Thus the purine fermentation is effected by four independent physio- 

 logical agents, 



1. guanasc, 2. adenas?, 3. xariliine-oxidase, 4. uncase. 



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

 about its destruction. 



Nucleic Acid 



guanine 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- 

 thineroxidase is shown by an examination of the livers of four different 

 species. (Jones and Austrian (a) (190G).) Ox liver forms uric acid from 

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



