IV 



THE JUNGERMANNIACEyE 



79 



oil, but that no rule could be made out as to the distribution 

 of the two sorts of cells. The latter are the spore mother cells, 

 while the others are gradually used up by the developing 

 spores. The latter remain united in tetrads, and escape from 

 the capsule by the gradual decay of its wall and of the sur- 

 rounding tissue of the gametophyte. 



The male plants are very much smaller than the females, 

 with which they grow and under which they are at times 

 almost completely hidden. The cell walls of the antheridial 

 envelopes are often a dark purple-red colour, and this makes 

 them much harder to see than the vivid green of the female 

 plant. The apical growth and origin of the antheridium is 



Fig. 31. — Sphcerocarpus terrestris z>ar. Cali/omicus. Development of the antheridium. A-D, 

 Median longitudinal sections, X450; E, an older one, X225; F, a spermatozoid, killed with 

 osmic acid, X900. 



the same as in Riccia. The first division in the primary 

 antheridial cell is the same as in that of the archegonium, but 

 the basal cell is smaller, and does not divide again transversely, 

 and takes but little part in the formation of the stalk. In the 

 antheridium mother cell are next formed two transverse walls, 

 dividing it into three superimposed cells. The two uppermost 

 divide, as in the Marchantiaceae, by vertical median walls into 

 regular octants, the lower by a series of transverse walls into 

 the stalk, which consists of a single row of cells sunk below the 

 level of the thallus. After the division of the body of the 

 antheridium into the octant cells, periclinal walls are formed 

 in each of these, so that the body of the antheridium consists 

 of eight central cells and eight peripheral ones, and the stalk 



