3°4 



BOTANICAL GAZETTE 



[OCTOBER 



length. 



The two extreme individuals are also given in the table- 



One showed elongation in water of 27.5 per cent and shrinkage 

 in the sugar solution back to 1.9 per cent; the other extreme 

 individual showed an elongation of 12.5 per cent in water and 

 shrinkage back to 2 per cent in the sugar solution. In all the 

 measurements of this section we find great variation between the 

 individual embryos. 



Table IX shows the elongation of 10 air-dry embryos, freed 

 from the seed coats at both ends, when they are placed in 2 volume 

 mol. cane sugar. 



TABLE IX 



Elongation of 10 Alisma embryos placed in 2 mol. cane sugar solution for 52 hours. 

 Seed coats removed at both ends of the embryos. 



Treatment of embryos 



Air dry 



5 hours in sugar solution 



20 u " u " 



40 " " « u 



52 a a a a 



— - - 



Total length of 

 embryos 



1080.0 

 IO93.O 

 1109.7 



HISS 

 11145 



Average length of 

 embryos 



Percentage of 

 elongation 



108.0 



109 

 III 

 III 

 ill 



3- 



o— 



3 + 



4 + 



1.2 + 



2.7+ 



3- 1 

 3- 2 



mbryos 



of 3 . 2 per cent. Allowing for considerable variation in individuals, 



same 



dry embryos are soaked directly in 2 mol 



<*x* u.lj ^LiLVLyvs aic sucu^cu unceuy ill z ulul. cane; su^ai ^/* »***w*- — 



they are first soaked in water for 2.5 hours and then transferred 

 to the sugar solution. The 19 per cent elongation of the embryo 



in the course of 2.< hours is all a matter 



imbibition 



intact 



as we shall see in 



the next section, elongates on the average 10 per cent when it is 



If* m mm - - « « 1 il .1 4-L* /-v 



soaked in water for a similar 



It is probable that 



embryo in the intact seed thus soaked elongates far less than 10 



mass at both ends of the em 



coat 



s. 



i show much swe 

 Were the embry 



-~ 



earn* on 



imbibitional 



the coat cap at the large end of the embryo 

 embryos would extend 10 ner cent of thei 



