550 Thiselton-Dyer . — Morphological Notes. 
phylls ; Fig. 5 is an ovule-bearing one. The cicatrix has 
expanded and become the more prominent feature in the 
sculpturing of the peltate expansion. Its surface is filled up 
with tubercles, which probably have some relation to the ends 
of the fibro-vascular bundles. 
Encephalartos brachyphyllus is remarkable for the relatively 
small number of carpophylls which compose its cone. These 
consequently attain an unusually large size. The terminal 
cicatrix is expanded into the large shallow depression already 
referred to, which occupies the greater part of the external 
surface of the peltate extremity. 
As already pointed out in E . villosus , the carpophyll is 
a reduced and modified equivalent of an entire foliage leaf, 
the pinnae of the lamina being represented by teeth. In 
E. longifolius , E. brachyphyllus , and other species, this is not 
so, and apparently nothing but the petiole or rhachis has 
contributed to the structure of the carpophyll. In Fig. 5 it 
will be noticed that the peltate extremity bears usually four 
more or less well-marked ridges ; two lateral and two vertical. 
These correspond to similar ridges on the foliar rhachis. 
In these cases the carpophyll is entirely petiolar. Below, 
and concealed by the peltate extremity, it bears a pair of 
ovules, one on either side. The interesting question suggests 
itself as to what is the homology of these. In Cycas, Sachs 
(Textbook, 2nd ed., p. 503) says ‘the lower pinnae are re- 
placed by ovules.’ Probably this is the ordinary view which 
would be taken for Cycadeae generally. But an ovule is 
a sporangial structure, and it is not easy to see anything in a 
pinna which is in any way comparable to it. Morphological 
conceptions must not enslave us, and I see no reason why 
sporangial structures, like buds, may not appear anywhere. 
