Botrychium simplex , Hitchcock. 453 
The second root of this plant (Text-fig. 10, B) was diarch, but the two 
groups of tracheides were unequal in size. 
The apex of the third root (Text-fig. 10, A) shows the characteristic 
tetrahedral initial cell, with somewhat irregular segmentation. The root- 
cap is derived in part from direct segments cut off from the apical cell, and 
in part from periclinal divisions in the lateral segments. 
The cotyledon probably emerges after about four roots have developed, 
and soon after, perhaps the next year, the second leaf appears above ground 
as a very small fertile frond (Figs. 17, 18, 19). The base of the petiole 
forms an elongated sheath, within which can be plainly seen the next 
Text-fig. io. a. Median section of the apex of the third root, x 300. b. Cross-section of 
the bundle of the second root, x 300. 
younger leaf. The lamina of the leaf is very small, with a slightly toothed 
margin and dichotomous venation. The sporangiophore is incurved and 
bears a very few sporangia. The one shown in Fig. 18 had only one 
perfect sporangium, and it may be that sometimes no perfect sporangia 
develop on this rudimentary sporophyll. 
The relation of the sterile lamina and the sporangiophore was not 
investigated, but it is highly probable that the two arise by an early 
dichotomy of the leaf-apex, such as Bruchmann found to be the case in the 
later leaves in B. lunaria. 
While the embryo of B. simplex agrees in the main with that of 
B. lunaria , the subordination of the foliar structures to the roots of the 
young sporophyte is much less marked. In B. limaria Bruchmann states 
that at least seven, and sometimes as many as nine, rudimentary leaves are 
