ON THE SELECTION OF RAPE SEED. 



441 



II. The relation between the absohite weight and specific 

 gravity of rape seed and its germination. 



III. The relation between the specific gra\it}' of rape seed 

 and its oil content. 



I. The Relation between the Absolute Weight and 

 the Specific Gravity of Rape Seed. 

 For experiment five different sorts of rape seeds were taken and 

 in the first place their average specific gravity and absolute weight 

 were determined, the former by means of the pycnometer and then 

 they were separated into eight lots of different specific gravities 

 with the solution of common salt. The results were as follows : — 



Sorts. 



Average specific 

 gravity. 



Average weight of 

 one grain. 



Chosen 



1. 1225 



3.1 1 mg. 



Okuna from Gumma 



1.I120 



3.21 



Hiroshima 



I 1 103 



3.22 



Hamburg 



1.158c 



3-15 



Colza 



1.1090 



2. C.J 



The seeds were first selected with the solution of common salt 

 of the specific gravity of 1.145, the floating portion was separated 

 and successively selected with the solutions of the specific gravity 

 of 1. 125, 1. 105, 1.085, 1.065, 1.045 and 1.025. In this way a series 

 of seeds having different specific gravities was obtained : — 



Series. Specific gravity. 



I I -145 ■''^"d more. 



n 1. 145— 1. 125 



III J. 125 — 1. 105 



IV 1. 105 — 1.085 



V 1.085 — 1.065 



VI 1.065 — 1-045 



VII 1.045 — 1-025 



VIII T.025 and less. 



Of a given quantity of rape seeds thus divided, those of I 

 having the highest sjoecific gravity, were least in number and the 

 grains were irregular in shape and size ; those of II were about 



