ciiapti<:r XI 



<;i:RM [NATION 



AVIXG ctjiisidered the j)rocesscs which 

 lead up to the formation of seed, we 

 ma\- now investigate the h'fe-history of 

 seed and its various forms. 

 Like fruits, seeds differ much in their 

 outward shape. In size alone we find a threat 

 contrast between the flust-like seeds of the (jrchids 

 and the huije seeds of the cocoa-nut-palm, while 

 between those two extremes we may note every 

 gradation of size. In other respects, also, the seed 

 offers no less variety of form and covering than 

 the fruit, such variations having relation to the 

 particular mode of dispersion and germination. 

 The outer skin or coat of a seed, called the testa, 

 offers a very interesting field of study, and such 

 seeds as the popp)' and siloic with beautiful net- 



