14 Jean White : 



cellular spaces below these contain liquid and not air. For 

 an air coliunn in a narrow tube forms an efficient barrier 

 to the entrance of a light liquid. Tlie contractions and expan- 

 sions of the air column due to the periodic temperature varia- 

 tions would cause the liquid which rests over the aperture to 

 be drawn in slightly or forced out, but only extremely small 

 quantitie-s of liquid mig-ht eventually gain entrance into the 

 cells from the exterior. 



Provided the intercellular canals be full of liquid as would 

 be almost invariably the ease in juicy varieties, the poisonous 

 solution would, as before, be drawn into the mouth of the 

 canal, where, by diffusion, some of it would remain in the 

 tube even after the next rise of temperature, and according 

 to the ordinary' physical laws, of diffusion the dissolved poison 

 would travel down the canal, and would then penetrate into 

 the interior of some cell. Acco^rding to this theory, therefore, 

 the more juicy fruits ought to be more susceptible to bitter 

 pit than the mealy ones. To test whether this was the case, a 

 series of experiments was performed by which the juice was 

 carefully expressed from equal weights of 3 different varieties 

 of apple, by using moderate pressure. 



Variety. . Weight of Material. Weitfht of Juice. 



Jonathan - - - 20 grms. - 7.05 grms. 



Anne Elisabeth - - 20 „ - 7.0 



Munro's Favorite - 20 „ - .4 „ 



The width of the cuticle and the thickness of the cell- walls 

 also vary in these 3 varieties. (See table.) (See figs. 9, 10, 11). 



It was found that a disease apparently similar to bitter pit 

 may l3e produced artificially by means of other poisons. Tlie 

 poisons employed for this were chloroform, corrosive sublimate, 



