CHAP. Ill MARCHANTIEJE 43 



surface the boundaries of these spaces form a definite network 

 which in Conocephalus (Fig. i, D) is especially conspicuous. 

 The bottom of these chambers is sharply defined by the colourless 

 cells that lie below, and the space within the chamber is filled 

 by a mass of short, branching, conferva-like filaments, which in 

 the centre of the chamber have free terminal cells, but toward 

 the sides are attached to the epidermal cells and are more or 

 less confluent with the adjacent filaments. 



As in Riccia root-hairs of two kinds are present, but the 

 thickenings in the tuberculate rhizoids (Fig. i i) are much 

 more pronounced, and these are not infrequently branched, 



A. 



Fig. 10. — Finibriaria Califo-nika (Harape). Development of the pores upon the archegonial 

 receptacle, X260. A, B, C, in longitudinal section ; D, view from above. 



and may extend nearly across the cavity of the hair. The 

 ventral scales are not produced by the splitting of a single 

 lamella, as in Riccia, but are separate from the first and 

 usually arranged in two rows. Leitgeb ^ recognises two 

 tyjDCs of these organs. In their earliest stages they are alike, 

 and both arise from papillae close to the growing point. In 

 both cases this papillae is cut off from a basal cell, but in the 

 first type {Sauteria, Targionia, Dimiortiera) it remains terminal, 

 usually forming the tip of a leaf-like terminal appendage of 

 the scale. In the second type, represented by most of the 

 other genera, this originally terminal papilla is forced to one 

 side by the development of a lateral appendage to the scale, 



^ Leitgeb (7), vol. vi. p. 17. 



