JOG 



on a very different kind of evidence froi.i that broueht for- 

 v.ard in the present paper. 



The evidence at liand seems to justify the following 

 conclusions: 



1. There is in Griffithsia a.n antithetic alternation 

 of generations, the gajnetophyte being represented Id;'- the 

 sexual plants, the sporophyte by the sporogenous cells of 

 the cystocarp, 



2, In addition to this, there is a regular succession 

 of tetrasporic individuals and sexual individuals. The 

 tetrasporic individuals resemble the sporophyte in niujiber 

 of chromosomes; they resemble the iametopiiyte in morpho- 

 logical differentiation. They are to be considered as a 

 phase of an homologous alternation of generations, not the 

 equivalent, wholly or in part, of the sporophyte of 

 Archegoniates , 



