IV 



THE JUNGERMANNIACE^ 



87 



formed, so that to the naked eye the archegonial receptacles 

 appear as densely fringed and flattened tufts upon the sides of 

 the larger branches. 



The earliest stages in the embryo are not perfectly known. 

 Kienitz-Gerloff^ investigated Metzgeria furcata and Leitgeb" 

 species of Aneiira. In both of these the first division in the 

 embryo separates an upper cell, from which capsule and seta 

 develop, from a lower cell, which forms a more or less conspicu- 

 ous appendage at the base of the foot. The earliest divisions 

 in the upper part are not known, but it soon becomes a cylindri- 

 cal body consisting of several tiers of cells, each composed of 



c 



A 



Fig. 36. — A, Young embr>-o of Anenira muliifidaijiwm..'), optical section, X235 (after Leitgeb) ;\B, 

 median longitudinal section of an older sporogonium of ^-J. p/n^m's (T)um.), X 35 ; C, upper part of 

 B, X 20c ; sp, sporogenous cells ; e/, young elaters ; i>i, apical group of sterile cells. 



four equal quadrant cells. According to Leitgeb,^ the upper 

 tier, from which the capsule develops, is formed by the first 

 transverse wall in the upper part of the embryo. This upper 

 tier is next divided by nearly transverse walls into four terminal 

 cover cells, and four larger ones below, and these latter are again 

 divided each into three cells, an inner one and two outer ones, 

 so that the capsule consists of four central cells, the arche- 

 sporium, and twelve wall cells (Fig. 36, A). A similar division 

 in the lower tiers results in the formation of four axial rows 

 and a single outside layer of cells in the stalk. In the 

 lowest tiers the divisions are much less regular, and the first, 



^ Kienitz-Gerloff (i). - Leitgeb (7), vol. iii. p. 47. ^ Leitgeb, /.c. 



