THE HIGHER CRYPTOGAMTA. 9 



tides of the cells of the covering layer of the antheridia, of 

 which several, to the amount of eight, are here found in 

 one cell. The antheridia, when fully ripe, open at the 

 apex, the cells of the covering layer parting asunder. The 

 contents, that is to say the lenticular vesicles before men- 

 tioned, emerge under water by degrees, and become 

 distributed in the surrounding fluid. The vesicles begin 

 to rotate slowly, during which the enclosed antherozoid 

 becomes free, apparently by the gradual dissolution of the 

 wall of the vesicle. It moves about slowly in the water, 

 rotating slowly round the axis of its spiral. 



The formation of the archegonia of Anthoceros differs 

 essentially from that of all other Hepatic. A single string 

 of cells, situated on the upper side of a young shoot, and 

 directed obliquely backwards and inwards, becomes filled 

 with granular mucilage. The cells of this row are arranged 

 in a straight line one above another, and form part of a 

 group of cells produced by the multiplication of an upper 

 cell of the second degree. There is no formation of chloro- 

 phyll-bodies in these cells (PI. I, fig. 4). The lowest of 

 the cells of this row swells up during the time that the 

 cells of the stem are increasing in number in the direction 

 of its thickness, and, consequently, before the number of the 

 cells lying between such lowest cell and the upper surface 

 of the stem has reached its limit (PI. I, fig. 4, a). In 

 the basal cell a free daughter-cell is formed, which, in- 

 creasing rapidly in size, soon fills up the greater part of 

 the mother-cell (PI. 1, fig. 16). The transverse septa 

 which divide the rest of the cells of the row from one 

 another are then absorbed. Thus there originates a narrow 

 open passage, filled with mucilaginous fluid, which leads 

 into the interior of the tissue of the stem, and into the 

 basal cell of the archegoniutn, which is now open above 

 (PI. I, fig. 17). Seen from above, this passage is a hexagonal 

 opening, bounded by six cells of the epidermis, and becoming 

 narrowed inwardly to a cylindrical canal (PI. I, fig. 18 h ). 

 By this means the spermatozoa, after their escape from the 

 antheridium, are enabled to reach the immediate neio-h- 

 bourhpod of the oval daughter-cell of the basal cell of the 

 archegonium. 



