SPORE-PRODUCING MEMBERS 453 
is shown by ‘comparison of Fig. 252 a and p. The similarity of these 
simple fertile spikes to those of the smaller species of Ophioglossum, such 
as O. Bergianum, is plain enough: if we imagine the sporangia in this 
plant to be somewhat more prominent, less bulky, and their position 
‘slightly altered, so as obliquely to face the sterile frond, the result would 
be such a type as is seen in the simplest forms of Botrychium. From 
these simple forms to the more complex, even to those in which the 
spike attains its largest development, is a progression which may be 
traced by very gradual steps: the first of these steps is illustrated by 
the Figs. 252 a, B, C: in the first figure (a) two lateral rows of simple 
sporangia are seen: in (B) the place of 
one sporangium is taken by two coherent 
together, while in the third (c) there are 
at the base of the spike, which is simple 
above, two “branches,” the one with two 
sporangia and the lower one with three. 
These specimens will illustrate the gradual 
steps towards branching of the spike which 
are to be found in the simplest types of 
Botrychium. Sections also bring out some 
interesting points: Fig. 252 E represents 
in outline under a low power a transverse 
section of a spike of Botrychium Lunaria 
traversing two of its lower branches longi- 
FIG. 252. 
tudinally, and following the series of their 
sporangia: this shows the acropetal succes- 
sion of development of the sporangia, while 
it will be noted that the two lowest on the 
right are coherent to form a synangium—a 
matter of common occurrence, and corre- 
Botrychium Lunaria,L. A,B,C=three 
very simple spikes. 4 shows no branching, 
but only two rows of sporangia, of arrange- 
ment like those of Ophzoglossum, but pro- 
jecting further. Band C show simple cases 
of branching enlarged. D, & show trans- 
verse sections of spikes; D close to the 
apex, £ lower down; the latter follows two 
branches longitudinally, and traverses their 
sporangia, Note the synangium on the 
right-hand branch. X about 20. 
sponding to what is seen in Fig. 252 3. 
Such simple observations as the above, which might readily be extended 
into further detail, will suffice to show that it is possible to illustrate, 
from simple though otherwise normal specimens, how a transition may 
have taken place from the condition of the spike similar to that of a 
small Ophzoglossum, through the simpler types of Botrychium to the more 
complex branched spikes. 
But it is in the large B. daucifolium that a better opportunity has 
been found of observing intermediate steps between the single normal 
sporangium and a twin pair of them: the series Figs. 253 a-c illustrate this : 
Figs. a, c show sections of young sporangia of normal type, with sharply 
curved contour: others are of broader form, and show a considerable 
mass of tissue on either side of the sporogenous group (Figs. D, E); 
in these there may be seen cells laterally adjoining the latter, and 
obviously .of similar origin and position (« in Fig. pb), which, though 
