300 Lang.—Development of Cycadean Sporangia . 
from this point of view, the main views recently expressed 
on the morphology of the Cycadean ovule by investigators 
who have studied the group must be shortly summarized. 
Since 1880, when the sporangium was definitely recognized 
by Goebel as an organ sui generis , the comparison between 
the ovule and a bud has been practically abandoned. The 
nucellus has been clearly recognized as corresponding to a 
sporangium ; the integument being regarded either as homo¬ 
logous with such an indusium as that of the Hymenophyllaceae \ 
or simply as a new formation. In his earlier work Strasburger 
regarded the whole ovule as corresponding to a sporangium, 
but in his latest statement 2 on the Gymnospermous ovule he 
definitely compares the nucellus with the sporangium, and 
adopts the view that the integument is a new formation. 
One point common to the estimate of the Cycadean ovule 
formed by both these observers and to the conclusion of 
Treub 3 , is the comparison of the ovule in this group with 
a sporangium enclosed within the tissues of the sporophyll, 
and not projecting freely from it, such, for instance, as the 
individual sporangia in the Ophioglosswn spike. In Cerato- 
zamia , the ovule of which he investigated, Treub recognized 
the appearance of the sporogenous group of cells within the 
sporangiferous lobe of the sporophyll and regards as a new 
formation the free upgrowth of nucellus and integument from 
the summit of the sporangiferous lobe turned towards the 
axis of the cone. 
In these views of the nature of the Cycadean ovule and 
the type of sporangium from which it may be derived, there 
is, so far as I am aware, no comparison instituted between the 
microsporangium and ovule, except as regards the sporo¬ 
genous group and the layers immediately surrounding it. 
Indeed the microsporangia and the ovules of Cycads have 
usually been compared with such very different sporangia as 
those of Angiopteris and Ophioglossum respectively. It is 
probable that this absence of direct comparison between the 
1 Warming, Syst. Bot p. 169. 2 Bot. Practicum, 3rd ed., p. 514. 
3 loc. cit., 1885, p. 48. 
