DECEMBER 



259 



dust is dropped, indeed sometimes thrown 

 to a little distance. This brown powder 

 consists of little grains each of which is a 

 spore, and these serve the plant for the pur- 

 pose that seeds answer in the higher plants. 

 But they differ in this, that, while a seed is 

 really a child of two parents, the spore is 

 but a piece of one. A seed, springing up, 

 will produce a plant with qualities between 

 those of its parents, with all the possibilities 

 of improvement on either that this fact 

 implies. A spore transmits practically un- 

 changed the qualities of its single parent. 



But the strange part of the process is 

 that when the spore grows it does not pro- 

 duce a fern at all; sprouting it grows into a 

 small heart-shaped shield. This is so in- 

 conspicuous as to escape attention on the 

 part of all but students and gardeners. And 

 it is this shield that comes nearest to flower- 

 ing in the sense of the crossing of individ- 

 uals to produce the new plant. For it is 

 from the crossing of two such shields that 

 a new fern arises. 



But not all the green is in the ferns and 



