1 2 Jean White : 



into the sucroses and invert sugars which characterise the ripe 

 fruit. But the dead cells composing the pitted areas always 

 retain their starch grains, clearly indicating that the diastase is 

 either destroyed or its action inhibited by some means. 



In my paper dealing with the enzymes and latent life of 

 resting seeds! it may be seen that enzymes are extremely re- 

 sistant, and something more drastic than the mere bursting 

 of the cells is required to suspend their action. 



All these symptoms in addition to the breaking down of the 

 cell walls in the centre of the nests of unhealthy cells could 

 only, to my knowledge, be produced by four agencies acting 

 singly or jointly. (See Fig. 8.) — 



1. By bacterial action. 



2. By fungal action. 



3. By cytase enzymes. 



4. By the action of a poison. 



The idea of the existence of any living organisms has been 

 almost universally denied by all investigators, and experiments 

 such as I performed at Burnley of trying to infect clean fruit 

 on the trees while still unripe, from pitted fruits, as well as 

 any attempts to produce cultures on gelatine or agar media, to 

 which apple juice had been added, failed to disclose the presence 

 of living organisms of any kind. 



As far as is known there are no cytase enzymes present in the 

 apple, and that leaves a poison as the only possible solution of 

 this phenomenon. Investigations on the diastase present in the 

 different stages of the development of the apple were continued, 

 and the results tabulated, as follows: — 



1 Proc. Uoy. Soc. London, ser. B., vol. Ixxxi, 1909, p. 441. 



