8o6 



Joiinidl of Agriculture . 



[lo Dec, 1910. 



The average results thus obtained from several experiments performed 

 on similar materials were as follows : — 



Pnlip of Sound Apples (Yates) 



Weight of Material. 



About GO -vms. 



\ Reaction to 

 Reaction to Feliling. Reaction to Biuret. ■ Tryptophane. 



Cytase. 



Sti-on 



. . Vc -y slight . . I 



No precipitate was thrown down from the affected cells of the pitted 

 specimens which were treated in exactly the same way, so that apparently 

 no enzymes are present, but as the experiments were performed on the cells 

 in about the most advanced stages of Bitter Pit, and as no material was 

 available in which the disea.se was in its earlier stages, nothing definite 

 can be stated in this way until next year's pitted crops are procurable. 



The above-mentioned enzymes were found to be present in the very 

 earliest stages of the formation of the fruit, the only differences whicn 

 were manifest being that the diastatic action produced by the enzymes 

 precipitated from the minced-up receptacles and ovaries before fertiliza- 

 tion was rather more pronounced, while the Biuret reaction was somewhat 

 less so. as shown in the following table : — 



Unpollinatei Receptacles of Apples {New York Pippin). 



The facts that there is no apparent difference between the enzymes 

 of the sound pulp of the pitted apples, and the pulp of the normal apples, 

 and that the enzymes are present in the rece[)tacles before pollination and 

 are absent in the most advanced stages of the di-^eased cells, show that 

 there must be some stage in the formation of the pit at which the enzymes 

 disappear. 



Whether this is a gradual or a sudden process can only be determined 

 by watching the coming crop for the first signs of pitting, and experiment- 

 ing on these specimens at regular intervals of time. Of necessity the 

 above comparisons were made between different varieties. It would 

 naturally be of importance to make similar comjiarisons between healthy 

 and disea.sed material of the same variety. 



As far as can be judged from the somewhat imperfect data at present 

 available, the enzymes appear to persist in the diseased cells for a short 

 time after these have died, which would appear to show that the disappear- 

 ance of the enzymes is not a cause of the disease, but is a secondary 

 consequence of it. 



Although the above investigations could not be fully completed until 

 the following and subsequent seasons, it has been judged advisable In 

 publish them now as far as they go, since it is probable that a special in- 

 vestigator will be appointed to carry out re.searches into the origin of this 

 disease, and it is necessary to leave the ground clear for his work. 



