CHAPTER IV 



THE ANTHOCEROTES 



This group contains but three genera, Anthoceros, Dendro- 

 ceros, and Notothylas, and differs in so many essential particu- 

 lars from the other Hepaticse that it may be questioned whether 

 it should not be taken out of the Hepaticse entirely and given 

 a place intermediate between them and the Pteridophytes. All 

 the members of the class correspond closely in the structure 

 of the gametophyte, and while showing a considerable varia- 

 tion in the complexity of the sporophyte, there is a perfect series 

 from the lowest to the highest in regard to the degree of de- 

 velopment of the latter, so that the limits of the genera, are 

 sometimes difficult to determine. The Anthocerotes are of 

 extraordinary interest morphologically, as they connect the 

 lower Hepaticae on the one hand with the Mosses, and on the 

 other with the vascular plants. Leitgeb ( (7), v., p. 9) has en- 

 deavoured to show that they are sufficiently near to the Jun- 

 germanniales to warrant placing them in a series with that 

 order opposed to the Marchantiales, but a careful study of 

 both the gametophyte and the sporophyte has convinced me 

 that this view cannot be maintained; and that while probably 

 the affinities of the Anthocerotes are with the anacrogynous 

 Jungermanniales rather than with the Marchantiales, never- 

 theless the two latter orders are much nearer each other than 

 the former is to either of them. 



The gametophyte in all the forms is a very simple thallus, 

 either with or without a definite midrib. Of the three genera 

 Dendroceros is confined to the tropical regions, while the other 

 genera occur in the temperate zones, but are more abundant in 

 the warmer regions, where they also reach a greater size. The 

 species of Anthoceros and Notothylas grow principally upon 



120 



