EMBRYOLOGY 475 
degree of uncertainty. In &. wirginianum it is traced by Jeffrey from the 
epibasal hemisphere, and his drawings seem to bear this out. But in 
O. vulgatum Bruchmann indicates a cell in the hypobasal region as the 
probable initial cell. It seems not improbable that in the Ophioglossaceae, 
as also in the genus Agw7sefum and among the Lycopodiales, the origin of 
the root is not uniform in position, but may in this relatively large embryo 
be at a point either above or below the primary segment-wall. 
A very striking feature in the young seedling is the early appearance of 
the fertile spike. In O. vuldgatum it may appear upon the third leaf, while it 
may be seen even on the first leaf of the adventitious buds of this species. 
In Botrychium Lunaria its minute representative may be found on the 
rudimentary underground scales of the embryo. In these cases the body 
actually seen does not seem to differ either in position or in origin from those 
produced on the later leaves. Such facts will have their bearing on the 
question of the morphological nature of the spike. Taken in relation to 
the general theory of sterilisation they indicate that the plants are but little 
removed from a condition where the very first leaves were fertile. On the 
other hand, Jeffrey figures several fairly advanced plants of B. wrgzntanum as 
having no spikes; but this species is one of advanced leaf-complexity. In 
Helminthostachys also, in which the leaves are large and complex, Lang 
has depicted young plants with expanded leaves, but without spikes. One 
is disposed to conclude from these scanty facts that the simpler-leaved forms 
of this family are more early fertile than those with more complex leaves, 
an indication of their more primitive state: but further data are necessary 
to substantiate the point, 
Lastly, there remains the case of B. obdguum, with its suspensor and its 
complete inversion of the polarity of the embryo. It is difficult to see how 
this is to be brought into relation to its biological surroundings. As the 
details of this aberrant embryogeny are not yet to hand, it must for the 
present be accepted as an objective fact, the chief interest of which lies in 
the demonstration that such differences as presence or absence of a 
suspensor, and consequent inversion of the initial polarity of the embryo, 
are possible within near circles of affinity: this will have its important 
bearing upon the comparison of /svezes, where as in most Ophioglossaceae 
there is no suspensor, with other Lycopodiales, in which a suspensor is 
present and the embryogeny inverted as in B. obliqguum. 
