64 Morphology BOOK i 



actual and potential gametophytes, or of sexual and neutral 

 forms. The relation of this alternation to the regular 

 sequence of the Archegoniatae and the place in it of the 

 fruit bodies of Coleochaete, the Florideae, and the Ascomy- 

 cetes, were, as we have seen, subjects of controversy. 

 Similarly, the origin of the sporophyte of the terrestrial form 

 was held by some to be the differentiation of a vegetative 

 form, fundamental to gametophyte and sporophyte alike ; 

 by others to be the intercalation of a new plant-body 

 derived entirely from the fertilized sexual cell. 



