aeria aie iif 
heat pentane 
raa" 
mne mH 
Se Vee 
- 
ON THE SEXUAL ORGANS OF THE CYCADACEX. 71 
the exostome, and hence it often happens in ripe fruits that the sum- 
mit of the woody part is prolonged into a tubular point.* 
The vaseular bundles, which are direct prolongations of one of the 
vaseular bundles of the earpophyll, pass through the cellular layer 
nearly to the summit, and in ripe fruits are closely applied to the 
woody portion. They do not anastomose, and their number varies in 
different genera and species, but usually they are grouped, as has 
already been stated, on opposite sides. Frequently they leave impres- 
sions on the woody layer. 
It seems, however, that in the formation of the coat all the tissues of 
the carpophyll are not equally developed. In Cycas revoluta, for ex- 
ample, and in the genera Zamia and Encephalartos, the epidermis is 
evidently continuous from one part to the other (Plate XCI. fig. 1); but 
in C. Rumphii the epidermis of the ovules is not densely hairy, like that 
of the carpophyll, and the ovules are surrounded at the base by a 
hairy ring, or cup-shaped dilatation of the carpophyll.t Up to what 
point the external layer of the coat is composed, on one side of a por- 
tion of the parenchyma of the carpellary leaf, and on the other of the 
whole, could only be determined when the development has been 
completely studied. From a superficial examination it might be sur- 
mised that the hairy cup of the ovule in the species belonging to the 
second division of the genus Cycas is of the same nature as the hairy 
‘surface of the ovules in C. revoluta. I have already (Analecta Bot. 
Indica, ii. p. 31) pointed out this distinction, which is not an unim- 
portant one. But in using the terms integumentum externum and in- 
ternum, I had no intention, in opposition to the opinion which I my- 
self have expressed as to the simple structure of the coat, of distin- 
guishing morphologically two distinct integuments. These expres- 
sions, possibly badly chosen, only apply to the external and internal 
ayers. 
I have already pointed out that the nucleus in Cycads is not deve- 
loped before its coat, but contemporaneously with it.f I have never 
observed its first appearance. In the course of its development both 
it and the embryo-sac pass through very different stages, and I was 
* (Plate XCI. fig. 4, 5.) This has also been stated by Karsten to be the case 
with Zamia muricata. 
t See, amongst others, the € = r4 mer, in Linnea, xxv. tab. 2. 
Karsten has confirmed n Zam ta. The nucleus and 
its coat appear ce aaaea o (Monatsb. Berlin. Akad., Dec. 18th, 1856.) 
