326 Durand : Marchantia polymorpha 



staining contents. I cannot confirm the statement of Strasburger 

 ('69) that this mother-cell is divided into two by a transverse wall, 

 but the first division-wall is obliquely vertical and curved, and 

 divides the mother-cell into two unequal cells {figs. 34, 35, 63). 

 The second wall is in the larger cell, and is likewise obliquely 



vertical and curved (figs. 36, 37), cutting both the first division- 

 wall and the wall of the mother-cell (fig. 38). A third similar 

 wall cuts both the first and second (cf. fig. 46). The young 

 archegonium has thus been segmented into an axial cell, triangular 

 in transection, bounded by three peripheral ones. The axial cell 

 is next divided by a transverse wall into a distal cover-cell and a 

 proximal mother-cell of the axial row (figs. 39, 40). The cover- 

 cell may segment at once (fig. 41), but more often it remains en- 

 tire for some time (cf. figs. 42-63). Ultimately it becomes 

 divided into four by two walls at right angles to each other (figs. 

 47 y 67> 57 y et se <I-)' Each of the three peripheral cells next divides 

 by a transverse wall near the middle (figs. 42, 43), and these are 

 soon followed by a corresponding one in the axial cell dividing it 

 into a proximal central cell and a distal neck-canal mother-cell 

 (figs. 44, 43). These last divisions have separated the young 

 archegonium into two regions : the neck and the venter. About 

 the same time each of the three peripheral wall-cells divides 

 radially so that the wall consists of six rows of cells (fig. 46). 

 Although the wall of the venter undergoes further radial division 



(fig- 59)> six remains the constant number in the neck (figs. 60, 

 66). 



Meanwhile the cell or cells immediately beneath the arche- 

 gonium, from which the mother-cell was originally derived, grow 



(fig* 



what 



(A 



what really becomes the proximal cells of the wall of the venter 



iff. fig 



A 



this has taken place unusually early. It will thus be seen that the 

 archegonium is not entirely derived from the original hemispherical 

 mother-cell. 



The young archegonium now undergoes a period of growth. 

 The axial cells elongate, the central cell becoming the larger with 

 a conspicuous nucleus. The wall-cells undergo repeated trail-- 



