1914] 



CROCKER &• DA VIS—DELA YED GERMINA TION 



3°9 



the embryo. 



great elasticity of the embryo as com 



mbry 



[ is also noteworthy. The results of this 

 proximate the force (imbibitional osmotic) 

 > of Alisma in the saturated condition is 



pressing against the coat; this approximates 100 



atmospheres (24, 27). 



Atkins (34) finds in certain legume seeds that 



only imbibitional forces are at work taking up water 



until growth actually begins; that is, a p 



asm 





elongation 



60 



agent (KN0 3 ) does not in- 

 hibit the rate or final total 

 amount of water taken up. 

 In Alisma seeds, whether the 

 coats are intact or not, as is 

 seen from the experiments in 



Time 



16 h 



20 h 



41 // 



Fig. 8. — Percentage of elongation of 13 Alisma embryos (coats removed at 



both ends) placed in water for 16 hours, then transferred to mol. cane sugar solution 



for 25 hours: measurements made on dry embryos, after 16 hours in water, and after 



5 and 25 hours in the sugar solution; i, curve for the 13 embryos studied; i', curve 



for the individual showing most swelling; i" , curve for the individual showing least 

 swelling. 



from 



1 previous sections, semipermeable membranes 

 he beginning. With the coats broken, it i 

 asmic membranes that are functional. It is 

 ►' findings are not of universal application. 



► very lik 

 evident tl 



