154 Worsdell, — The Structure and Origin of the Cycadaceae. 
Having regard to the Neuropteridean affinities of modern Cycads 
I should consider their cones as the final result of an extreme reduction 
of the erstwhile complex sporophylls, combined with a compact aggregation 
of these latter on a special portion of the main axis of the plant 1 . The 
sporophylls still retain a dorsiventral symmetry. On the female side the 
sporangia may be said to have just lost their primitive terminal position, 
for they are no longer on the actual margin but on the lower surface of 
the sporophyll. On the male side they are situated entirely on the lower 
surface, with no suggestion of a former marginal position, except in the 
case of Zamia , where they occupy much the same position as do the ovules 
on the female side. The genus Cycas is of great interest, for whereas the 
male sporophylls are reduced and arrayed in a cone, as in other genera, 
the female sporophylls constitute appendages of the vegetative portion of 
the stem. They are distinctly leaf-like, bear rudimentary pinnae in their 
upper portion, and a larger number of ovules than in the case of other 
genera. These ovules are also more primitive both as regards their size 
and also as to their position on the sporophyll, for they are borne termin- 
ally on extremely short, lateral outgrowths of the rachis, which may be 
regarded as the equivalents of the pinnae in the upper portion of the organ. 
Hence we may consider the female sporophyll of Cycas as approaching 
much more closely that of its Pteridospermic ancestor than is the case 
with other Cycads. 
I formerly regarded the question as to the origin of the Cycadean 
sporophylls from a much too general standpoint. From the point of view 
of plant-evolution as a whole, I believe my statements will still hold good, 
but will require some modification as regards the minor cycle of evolution 
which concerns the Cycads alone. In 1898 I stated that ‘the original 
type, viz. that in which the sporangiferous organs were distinct from the 
assimilating leaves, probably persisted right through, even down to the 
present day. From such forms as these latter I imagine it to be quite 
conceivable, and even probable, that modern Cycads took their origin.’ 
In the light of recent discoveries as to the origin of Cycads this statement 
must now be retracted. 
In conclusion, I may say one word as to the morphology of the ovular 
envelopes. I must side wholly with Celakovsky in maintaining that the 
law of uniformity demands that throughout Gymnosperms, to say nothing 
of higher and lower plant-forms, the sporangium must possess two integu- 
ments or the equivalents of such. In the ovule of Cycads there is no 
obvious representation of these ; yet the comparison of the seeds of allied 
forms, both fossil and recent, show that two integuments are probably present, 
although so intimately and congenitally concrescent as to give to the whole 
envelope the appearance of a primaeval integrity. In Lagenostoma , the 
1 This may have also happened in the case of Bennettites on the lateral branches. 
