Evans : Genus of Hepaticae from Hawaiian Islands 09 



as if they were repeatedly dichotomous. In the second or " inter- 

 calary branching,"* the branches are endogenous in origin and 

 postical, arising in the axils of the underleaves. They develop at 

 some distance from the apex, starting just inside the cortical cells 

 of the axis and forcing these apart as they elongate. Around the 

 base of such a branch, it is possible for a long time to find the re- 

 mains of these ruptured cells in the form of an indistinct sheath. 

 In Bazzania, these intercalary branches are always specialized, 

 sometimes as the very short sexual branches but more commonly 

 as the long and slender root-like flagella with their rudimentary 

 leaves. Both of the kinds of branching just described for Baz. 



aiua 



dinary 



(Fig. 3) and the sexual branches (Fig. 2) arising in precisely the 

 same way in the two genera. In rare cases, nevertheless, the 

 Hawaiian plant will show an ordinary leafy branch springing from 

 the axil of an underleaf and therefore intercalary in nature like the 

 vegetative branches of Kantia and of the typical species of 

 CepJialozia. 



The peculiar branches of the new genus are the flagella. 

 These are similar in appearance to those of Bazzauia, except that 

 they bear small but distinct leaves near the base ; but their place 

 of origin is very different. Instead of developing in the axils of 

 the underleaves, each flagellum arises at one side of an underleaf 

 ( Fi g- 4) ; instead of being surrounded by an indistinct sheath, 

 showing that it is endogenous in origin, it is naked at the base 

 and is, therefore, exogenous in origin ; the underleaf, finally, be- 

 side which a flagellum is situated, is much narrower than an 



ordinary underleaf. All of these conditions point to the fact that 

 we have to do here with a terminal branching in one of the postical 

 segments of the apical cell. This is made even more evident by 

 a study of the apical region, and in this connection it is instructive 

 to compare what we find in this plant with what is found in the 

 apical region of the closely related Bazzauia. 



The early stages of the leaves and underleaves of Bazzania 

 tnlobata have been carefully figured and described by Leitgeb.f 

 In this species he finds that the lateral segments cut off from the 



I-eitgeb, /. c. 2 : 30-33.//. 4 . f. 7 - 9 . 

 t L. c. 2: 10, 11, \t,. pi. 4 . 



