Bitter Pit in Aiyples. ■ ^7 



tsliglitly hiowiied woulii show that a truce of lioe oxyjj;eii was Btill 

 present in the pulp. 



After four weeks the sipples were collapsod, and the surface 

 wrinkled for the most part, tlie pulp dead ainl s]i<j;htly l)rowned, 

 ])ecoining veiy dark on exposuie to an-. Portions of living pulp 

 Averaging one-fourth of the hulk in some parts e.xtended fiom the 

 surface to the core. 



After six weeks in ('0.,, all were dead, the tiisl jioitioiis dying 

 being distinctly biown. tlie later poiti(nis to die l)ciug ])ractically 

 uncoloured until air was admitted. 



Evidently the air is only slowly lemoved from an \inpeeled 

 ivpple in an atmosphere of carbon dioxide. Using hydrogen, similar 

 results were obtained, but death took place in four to five weeks, 

 probably owing to the more rapidly diffusing hydi-ogen removing 

 the air from the apple more rapidly. 



Apparently a Yates' apple is not capable of more than a month's 

 strict anaerobiosis, and carbon dioxide has no poisonous action on 

 the pulp cells, acting simply by replacing air. 



Experiments were also tried on the effects of covering the skin of 

 Apples with comparatively impermeable films, and of immersing 

 them in liquids in which oxygen is more or less soluble than it is in 

 water. Of these the results obtained under kerosene and with gela- 

 tine films are of most interest. 



Apples immersed iii kerosene. 



Peeled apples under a deptli of two to four inches of kerosene 

 remained a pale greenish colour for fourteen days, and the pulp 

 cells were turgid and living. In three weeks they turned soft, and 

 slowly acquired a broAvnish colour, duller and not so dark as iu 

 ui)-. From the surfaces small plasmodium-like masses of granular 

 wdiitish material exuded, which later appeared to grow over the 

 whole surface as a white felt-like moss. This consisted of very 

 fine, much-branched threads, with no spores and few or no trans- 

 verse partitions. The appearance was as though a giauular Plas- 

 modium had turned into a filamentous mycelium. 



Slices of raw potato infected with the mycelium developed under 

 kerosene Avhite sunken patches at each point of infection, ramify- 

 ing at first in the substratum, but later more on the surface, the 

 threads being somewhat coarser, and more septate than on the 

 apple, possibly as the result of better nourishment. Over the unin- 

 fected surface and on uninfected slices, small whitish granular 

 plasmodium-like exudates appeared, turning later brownish. These 



