GERMINATION OF THE SEED. CHAP. I. 



absorption of moisture. But it was not yet pre- 

 cisely ascertained by what particular medium the 

 moisture had entered ; whether by the whole of the 

 surface of the envelopes, or only by a particular point. 

 The latter part of the alternative was soon ren- 

 dered the most probable. 



Mr. Gleichen, having steeped some peas in water 

 for the space of twenty-four hours, observed that 

 when they were pressed between the fingers the 

 water issued from the scar. It seemed therefore 

 likely that it had also entered by the scar, and in 

 order to ascertain the fact he covered the scar of a 

 few seeds with wax, and then put them in water. 

 But the result was that they did not absorb so 

 much moisture in several days, as they had ab- 

 sorbed without the varnish in so many hours. He 

 observed also that peas with the scar varnished did 

 not germinate. It followed therefore that water 

 penetrates the seed chiefly by the scar. A slight 

 degree of doubt, however, seems to have been at- 

 tached to this conclusion in consequence of some 

 experiments of Senebier, who in repeating those 

 of Gleichen found that seeds did not refuse to 

 germinate, even when the scar was luted. But as 

 he acknowledges at the same time that he was 

 not quite certain whether his lute was water-tight, 

 it is to be presumed that Gleichen's experiments 

 were correct. 



The moisture then necessary to germination pe- 

 netrates the seed chiefly by the scar; but partly 



4 



