74 
H. F. Wernham. 
What, then, is the general aspect of the primitive flower? 
The evolutionary origin of the angiospermous flower has formed 
the subject of a vast amount of discussion ; and this latter has been 
rendered largely abortive by reason of the extreme paucity of the 
geological record. We have been driven, in consequence, to the 
comparative study of existing forms in the search for light upon this 
all-important question. This study has been combined as far as 
possible with fossil evidence, but the result has, for reasons which 
will be suggested presently, proved far from satisfactory. 
The views respecting the primitive flower seem to have fallen 
into two main groups, determined, in the first instance, by 
emphasizing the individual sporangium, and in the second instance, 
by emphasizing the sporophylls. If, for the sake of clearness, we 
may anticipate for a moment, the former set of views contemplates, 
as a primitive flower, a single sporangium borne terminally, and 
naked,— i.e., unassociated with a perianth ; while the latter has for 
its primitive flower an aggregation of sporophylls, some fertile and 
some sterile, all indefinite in number, and arranged upon an axis 
more or less elongated, in a manner analogous to the arrangement 
of the vegetative leaves. 
The contemplation of the individual sporangium has, it is urged, 
been unfortunate in its results, so far as the evolutionary history 
of the flower is concerned. This point of view would appear to 
have arisen from the burning question of the evolution of the seed. 
In this latter question, emphasis has necessarily been laid upon the 
individual megasporangium ; and geology, so sparing in its assistance 
to the solution of the past history of the flower, has proved 
abundantly generous in its guidance where the problem of the seed 
habit has been concerned. 
The gulf does not at first sight appear to be a wide one between 
the female sporocarp of Azolla and the female flower of Najas. In 
both we have a single megaspore enclosed within its sporangium ; 
the sporocarp wall in the former is readily regarded as the analogue, 
if not the homologue, 1 of the integument in the latter, while a 
perianth is absent in both cases. We have only to suppose fusion 
between the sporocarp and sporangium walls in Azolla, together 
with infolding of the sporophyll to form a closed chamber, to 
produce the Najas flower, or something nearly resembling it. 
Closer consideration, however, appears to cast serious doubt upon 
the propriety of regarding the apparent narrowness of this gulf as 
* Celakovsky. 
