BKITISH MOSSES. 



3t 



ground and the stem is very short. In like manner the 

 sporangium (a) is almost sessile, and is seen almost 

 enshrouded in the leaves, true rootlets or rhizoids (r) 

 attach the plant to the ground, and the protonema (p) from 

 which the plant has arisen survives and remains attached 

 to it during the whole life 

 of the plant. This proton- 

 ema often exists in great 

 quantity in the clay banks or 

 fields where the Phascum 

 dwells, and forms a sort of 

 tangled mat. 



Again, in zoological em- 

 bryology, an attempt is often 

 found, to use the language of 

 Prof. Milnes Marshall, " to 

 escape from the necessity of 

 recapitulating, and to sub- 

 stitute for the ancestral process a more direct method." 



In like manner we have already seen to how great an 

 extent Nature has adopted the system of short-circuiting 

 in the reproduction of the Mosses ; for in every mode of 

 reproduction, except that through sporogone and spore, a 

 shorter circuit is travelled. We have seen how in every 

 case Nature seems to leave out the sexual reproduction if 

 she can help it, and directs her whole attention to the 

 production of the vegetative organism the Moss plant in 

 the popular sense which she never omits. 



Another point of comparison arises, but this time it is one 

 of contrast between the embryology of the two kingdoms. 



Fia. 17. Phascum cuspi- 

 datum. a, capsule; r, rhizoids; 

 p, persistent protonema. After 

 Schimper. 



