THE ARCHEGONIAT^E 



215 



The sporophyte remains included within the calyptra until the 

 spores are ripe, when there is a sudden elongation of the seta, which 



FIG. 174. A, Aneura multijida. Young embryo, optical section (X 235). (After 

 LKITQEB.) B, A. pinguis, longitudinal section of young sporophyte (X35). 

 C, upper part of B (x 200) ; sp., sporangenous cells; el, young elaters; m, apical 

 mass of sterile tissue. 



may increase many times in length within a few days, owing to the 

 stretching of the cells, brought about by the consumption of the sub- 

 stances within the cells. In Pellia 



epiphylla, the seta has been ob- rj$Q( ^ 



served to increase from one milli- x?r&V^ 5-, ,O 



metre to nearly eighty millimetres 

 in three or four days. This extra- 

 ordinary growth is at the expense 

 of starch which fills the cells of 

 the young seta. The capsule usu- 

 ally opens by four valves, but this 

 is not always the case. 



Suborder II. Acrogynae 



The acrogynous Jungermanni- 

 ales comprise the larger number of p IG 

 the described species of Hepaticse, 

 but the type is a much more fixed 

 one than that of the Anacrogynae. 

 Such foliose forms among the latter group as Blasia, Fossombronia, 

 and especially the peculiar genus Treubia, are intermediate, to some 

 extent, between the Anacrogynse and the Acrogynse; but the num- 



175. Madotheca Bolanderi. A, 

 female, B, male, plants (X 4) ; ?, 

 archegonial branch; , antheridial 

 branch. 



