372 GENERAL MORPHOLOGY OF PLANTS 



tophyte is the prothallium of first generation, and bears the 

 sexual organs, sperms and eggs; the fertilized egg develops the 

 sporophyte, the fern plant which bears the asexual spores. The 

 formula may be written as follows: 



Gametophyte<^ ^Fertilized egg Sporophyte asexual 



spores Gametophyte, etc. This formula abbreviated is 

 G / S \FE S asp G, etc. 



Diagram V, Illustrating the life cycle of a fern or Pteridophyte. Course of develop- 

 ment follows the direction indicated by the arrows. Zygote equals fertilized egg. Vegeta- 

 tive multiplication by buds. Note the increase of the sporophyte and decrease of the 

 gametophyte. 



