7 8 WorsdelL—The Structure of the 
not only the order Coniferae, but all three orders of the 
Gymnosperms, where before we but recognized a considerable 
amount of diversity. Hitherto, it has been regarded as a 
matter beyond all controversy that the sporangium in Coni¬ 
ferae possesses but a single integument; that the fleshy 
envelope of the Taxeae is either of the nature of a disk or 
special envelope or aril of no morphological value, as in Taxas , 
or that it represents the outer layer or layers of the single 
integument, as in Cephalotaxus , comparable to the case of the 
Cycads. Yet the sporangium of Podocarpus was, strangely 
enough, regarded as unique in possessing two integuments. 
Celakovsky’s theory, however, introduces us to a plan of 
perfect uniformity of structure in this respect throughout the 
entire order. For he maintains the constant presence through¬ 
out the order of not one, but two integuments to the 
sporangium, thus abolishing the awkward inconsistency of 
the presence of such extra and unusual organs as an aril, and 
the unique possession by Podocarpus of two integuments. 
There is nothing unreasonable in supposing outer integu¬ 
ments capable of becoming modified in the direction of vegeta¬ 
tive development to subserve the special adaptive function of 
a protective covering to the sporangia. The outer integument, 
forming an integral part of the sporangium, would, probably, 
if developed as Celakovsky suggests, as a protective scale, 
afford greater security to that organ than would the bract, in 
whose axil the sporangium would lie more or less indepen¬ 
dently of the latter or, at least, not so intimately bound up 
with it as it is with the seminiferous scale. 
In view of the comparatively one-sided nature and narrow 
scope of the views advanced by other writers on this subject, 
it appears to me probable that, in the near future, a theory 
of the structure of the female ‘flower’ in Coniferae, if not 
absolutely identical with, yet approximating most nearly to 
that which in recent years has been elaborated by Celakovsky, 
will occupy a paramount place in the minds of the foremost 
botanists of the day. 
