GROUP II. BRYOPHYTA. 



329 



destitute of stomata. It is true that in some Hepaticee (e.g. 

 Anthoceros, Marchantia, etc., Fig. 241) there are structures in 

 the superficial layer which are erroneously called stomata ; these 

 are merely pores, and differ altogether in structure and develop- 

 ment from the true stomata which are to be found on the 

 sporophyte of Anthoceros and of most Musci, as well as on the 

 sporophyte of the higher plants. 



The SPOROPHYTE, the 

 asexual spore - producing 

 form, is developed from the 

 oospore within the venter 

 of the archegonium (Fig. 

 237) ; its development is 

 direct and holoblastic. The 

 oospore divides first into 

 two cells by a transverse 

 wall, the basal wall, at right 

 angles or obliquely to the 

 long axis of the archegon- 

 ium ; the upper cell, the 

 one next the neck, is termed 

 the epibasal cell, the lower 

 the hypobasal cell. This is 

 followed in some Hepaticee 

 (March antiaceae, Antho- 

 cerotaceae) by the formation 

 of two walls, at right angles 

 to the basal wall and to 

 each other, which are known 

 as the quadrant and octant 

 walls, since they respectively 

 segment the oospore into 

 quadrants and octants of a 

 sphere. In other Hepaticse, 

 and generally in the Musci, 

 the segmentation into oc- (x about40 -) 



tants is confined to the epibasal cell, the hypobasal cell either 

 remaining undivided, or dividing irregularly. With the exception 

 of some of the lower Hepaticaa (Riccieee), where epibasal and hypo- 

 basal cells alike contribute to the formation of the capsule in 

 which the spores are developed, the epibasal cells alone give rise 



FIG. 237. Funaria hygrometrica. A Develop- 

 ment of the sporogonium (/ /) in the ventral 

 portion (b b) of the archegonium (longitudinal 

 section x 500). S C Different further stages of 

 development of the sporogonium (/) and of 

 the calyptra (c) ; h neck of the archegonium. 



