V THE ANTHOCEROTEJL 151 



in the early stages, it must be assumed that its structure in the 

 Anthoceroteae is radically different from that of the other 

 Liverworts. Of the lower Hepatica; Sphcerocarpus perhaps 

 offers again the nearest analogy to NototJiylas, but it would not 

 be safe at present to assume any close connection between the 

 two. Of course the very close relationships of the three genera • 

 of the Anthoceroteae among themselves are obvious. 



On the whole, then, the evidence before us seems to indicate 

 that the simplest of the existing Hepaticae are the lower thallose 

 Jungermanniaceae, and of these Sphcerocarpus is probably the 

 most primitive. The two lines of the Marchantiaceae and 

 Jungermanniaceae have diverged from this common ancestral 

 form and developed along different lines. The Anthoceroteae 

 cannot certainly be referred to this common stock, and differ 

 much more radically from either of the other two lines than 

 these do from each other, so that at present the group must be 

 looked upon as at best but remotely connected with the other 

 Hepaticae, and both in regard to the thallus and sporophyte has 

 its nearest affinities among certain Pteridophytes. The possi- 

 bility of a separate origin of the Anthoceroteae from CohocJicete- 

 like ancestors is conceivable, but it seems more probable that 

 they have a common origin, very remote, it is true, with the 

 other Liverworts. 



