468 OPHIOGLOSSALES 
cotyledon, which is itself green and expanded, emerges upwards, while 
the axis is still further delayed than in O. vulgatum: it may be suggested 
that the latter has been slipped out from the prothallus owing to the 
early elongation of the base of the cotyledon, and so its original genetic 
connection is not easily followed, and its appearance comes to be like 
Fic. 261. 
Botrychium virginianum, Sw. The 
upper figures show two embryos; the 
arrows show the direction of the 
archegonial neck. x=shoot ; y=root; 
J=foot; a=initial cell of shoot; d= 
initial cell of root. Xx250. The lower 
figure shows an embryo more advanced ; 
s=stem ; 7=root; c=cotyledon; cal= 
calyptra. X50. (From Jeffrey.) 
that of an adventitious bud. Or possibly in this, as apparently in the type 
of O. pendulum, the primary axis may be arrested completely (a step in 
advance on the vu/eatum-type), and the adventitious shoots described as 
originating on the root be actually such: in fact, early representatives of 
those so often found on the roots of the genus. But from the facts, as 
presented by Campbell, which are far from giving the complete develop- 
mental story, there does not appear to be sufficient reason to regard the 
