173 



conspicuous nuclei. The cells of the foot are larger and much 

 more transparent. 



The second type of embryo (Figs. 1 20, 1 29) reseml)les closely 

 a certain stage of the embryo of 0. ruhjatuin (Brdchmann, 

 Fig. 58) where, as Bruchmann says, the embryo is "all root". 

 He considers that the root and foot are l)oth of liypobasal 

 origin, but he bases this rather on a comparison witli the true 

 ferns than upon actual study of embryos, as he was unable 

 to obtain embryos sufficiently young to demonstrate this, and 

 all trace of the original divisions disappears before any sign of 

 the stem and leaf is evident. It may be well questioned 

 whether, as in Botrychium and 0. pendulum the foot does not 

 take up the whole hypobasal region. It is not impossible that 

 the position of the basal wall may also vary in 0. ruhjdtum. 

 From a comparison with the embryo of 0. pendulum the writer 

 is inclined to assign more of the embryo of 0. vulgatum to 

 the foot region than is done by Bruchmann. 



In 0. vulgatum, however, there is finally a differentiation of 

 the stem apex from the epibasal region, as in Botrychium and 

 the true ferns, while, as we shall see, in 0. pendulum the 

 embryo develops simply the primary root, from which (or 

 possibly independently, from the sister quadrant) the second 

 root is developed, and there is no trace either of stem or leaf. 

 These first appear upon a bud which develops endogenously 

 from the older root. 



While in 0. moluccanum, the prothallium probably only lives 

 for a single season and the formation of the sporophyte stops 

 its further development, in 0. pendulum, where embryos are 

 much less frequently found, the large gametophyte continues 

 its growth apparently unchecked by the development of the 

 attached sporophyte, which retains its connection for a very 

 long time, as in 0. vulgatum. and Botrychium virginianmn. 



The embryo reaches a very large size before it breaks through 

 the prothallium. The primary root then pushes through, as a 

 conical point (Fig. 40). The second root remains short for a 

 time. There seems to be a wood deal of difference as to the 



