Abscission of Flowers and Fruits of the Apple 



97 



expressed from apples whose seed content was known. A single apple 

 did not yield sufficient sap, hence three or four fruits with the same num- 

 ber of seeds were used in each case. The apples were first ground up 

 in a food chopper, and the sap was then expressed from the pomace. 

 The freezing points of this sap were obtained by means of a Beckman 

 apparatus. The results are given in table 47, which shows that the sap 

 from fruits with few seeds depresses the freezing point less than does 

 the sap from many-seeded fruits. It should be pointed out, in this con- 

 nection, that these freezing points are for sap expressed from the live 

 tissue of the fruits. If the tissue had been frozen before the sap was 

 expressed the depression of the freezing point would no doubt have been 

 greater in each case. 



TABLE 47. Depression of Freezing Point by Sap from Fruits with Varying 



Numbers of Seeds 



Variety 



Sap from fruits with 

 few seeds 



Number 

 of seeds 

 in fruit 



Depression 



of freezing 



point 



(degrees 



centigrade) 



Sap from fruits with 

 many seeds 



Number 

 of seeds 

 in fruit 



Depression 



of freezing 



point 



(degrees 



centigrade) 



Tompkins King 



Baldwin 



Westfield 



Fallawater .... 



Baldwin 



Rhode Island. . 



Average . . . 



081 

 123 

 972 

 009 

 0.809 

 0.900 



0.982 



6 

 6 

 9 

 5 

 6 



5 



6.2 



1 .119 



I 153 

 1 .024 

 1 .027 

 0.909 

 0.967 



I 033 



The average weight of the spurs and of the fruits is given, in con- 

 nection with the number of seeds and the depression of the freezing point, 

 in table 48. These data likewise indicate that the sap of many-seeded 

 fruits is capable of developing a greater osmotic pressure than the sap 

 from few-seeded fruits. This fact suggests why the many-seeded fruits 

 do not lose water as readily as do the few-seeded fruits. 



That the term greater seed value is more nearly accurate than many 

 seeds is indicated by the last experiment in table 48. The eight-seeded 

 fruits in this case have a lower seed value than the three-seeded fruits. 

 As would be expected under such conditions, the three-seeded fruits show 

 the greater sap density. 



211 



