454 OPHIOGLOSSALES 
corresponding in every other respect, do not assume the dense 
protoplasm of sporogenous cells. These more bulky sporangia lead 
on to such as that shown in Fig. 253 5, in which it is possible 
that the whole sporogenous group is referable to a single parent cell, 
though the proportions of the whole group are quite different from those 
of the typical sporangia; the sporogenous cells appear, however, to form 
two groups, and probably originated from two similar cells side by side. 
The interest of this lies in the fact that these broad sporangia approach 
Fic. 253. 
Botrychium daucifolium, Wall. A and C, successive stages of the most common type 
of sporangium, B=asmallsporangium ofnarrow form. D=avery broad sporangium; the 
cells marked (x) correspond to the sporogenous group, but showed no signs of developing 
further as such. =a still broader sporangium with wide sporogenous group, referable 
to two parent cells, possibly ultimately to one. #, G=synangia cut transversely and 
vertically. X 200. 
in their form and bulk to the synangia which, as above noted for 
Botrychium Lunaria, are not unfrequently found; one of these, cut 
through transversely, is shown in Fig. 253 F; here there is a zone of three 
layers of sterile tissue forming a septum between the two sporogenous 
groups. The septum is, however, commonly broader than this: if a 
comparison be made between this and the young synangia of Zmesipterts 
the similarity will be readily seen. Such examples as these, which can 
easily be found in sections of the fertile spike, illustrate the gradual 
transitional forms which may be traced between the simpler and more 
complex spikes of the genus. Whether these steps will bear an evolu- 
tionary interpretation, as illustrating the manner of advance from a 
