VI MOSSES {MUSCl): SPHAGNACEAi—ANDRE.'EACE^ 1.77 



space between the inner and outer spore-sacs becomes very- 

 large to accommodate the growth of the numerous spores. 

 The pseudopodium is exactly the same as in Sphagmun, and 

 the vaginula and calyptra are present. The latter is much 

 firmer than in Sphagnum, and like that of the Bryineai. 



ArcJiidium 



The genus ArcJiidium is one whose systematic position has 

 been long a subject of controversy. It has usually been associated 



Fig. 84. — Archidhiin Ravcnclii (Aust.)- A, Median section through a nearly ripe sporogonium, 



X 90 ; B, base of the sporogonium, x 270. 



with' the so-called cleistocarpous Bryineai, but the researches of 

 Leitgeb seem to point to a nearer affinity with Andrecea. 



The species of ArcJiidium are small Mosses growing on the 

 earth, and especially characterised by the small number, but 

 very large size, of the spores contained in the sessile globular 

 sporogonium. Hofmeister ^ was the first to study the develop- 



^ Hofmeister (i), p. 160. 

 N 



