XIII LYCOPODINE^ 519 



suspensor enlarges somewhat, and forms a bulbous body, which 

 completely fills the venter of the archegonium. The suspensor 

 grows rapidly downward, penetrating the diaphragm and push- 

 ing the young embryo down into the mass of food cells which 

 occupy the space below it. The suspensor is very irregular 

 in form, and undergoes several divisions (Fig. 298, G). 



The first division in the embryo proper is almost vertical 

 (Fig. 298, F), and divides it into nearly equal parts. Beyond 

 this the early stages ot che embryo w^ere not followed by the 

 writer, but to judge from the later stages, they correspond to 

 those of S. Marteusii, which has been most carefully studied 

 by Pfeffer ( i ) , the substance of whose work may be given as 

 follows. After the first w^all is formed in the embryo, there 

 arises in one of the cells a second, somewhat curved one, which 

 strikes the primary wall about half-way up. The cell thus cut 

 of¥, seen in longitudinal section, is triangular, and is the apical 

 cell of the stem (Fig. 299, A). The two other cells (leaf- 

 segments) now undergo division by a vertical wall, which 

 divides each into equal parts, and each of these pairs of cells 

 develops into a cotyledon. The apex of the young cotyledon 

 is occupied by a row of marginal cells in w'hich divisions are 

 formed, like those in the apical cell of the stem, and in longi- 

 tudinal section the apex of the cotyledon seems to have a single 

 apical cell, much like the stem (Fig. 299, E). From the larger 

 of the leaf-segments, by a more active growth of the cells next 

 the suspensor, the foot is formed, and by its growth the stem 

 apex is pushed to one side, and its axis becomes almost at right 

 angles to that of the suspensor. Each cotyledon develops upon 

 its inner side, near the base, an appendage, the ligula (Fig. 

 300, /), which is a constant character of all the later leaves. 



The primary root, as in Lycopodium, forms late, and no 

 trace of it can be seen until the other parts are evident. It 

 arises in the larger leaf-segment, close to the suspensor, and 

 therefore is separated from the cotyledon by the foot. The 

 root-cap arises from a superficial cell, w^hich divides early by 

 both periclinal and anticlinal walls, and thus becomes two lay- 

 ered. From a cell immediately below is derived the single 

 apical cell to wdiich the subsequent growth of the root is due. 

 The further divisions in the primary root were not followed. 



The axes of the stem and root soon develop a strand of 

 procambium which is continuous in the two, but to judge from 



