212 DEVELOPMENT OF THE OVULUM 
observable, the boyaux did not even reach to the end of the 
stigmatic canal. Still impregnation was almost universal.* 
On the setting in of the fine weather, I recommenced my 
observations which had been interrupted on account of the 
above circumstance. I have since examined many ovula at 
different periods, and I have found the penetration of the 
boyaux into the ovula very general. The examinations 
took place with the same means, and give rise to doubts 
as to the universal necessity of the final penetration of the 
pollen tubes. 
NELUMBIUM,—DESCRIPTION OF PLATES LV. LVI. 
The nucleus is visible at a very early period, when the flower 
bud is half developed it has a central cavity!!! or excavation. 
Pl. 55, 1., Represents the nucleus of an ovule : into the se- 
cundine of which a membrane had been introduced in all pro- 
bability in continuation of the cap. "This membranous pro- 
longation was excessively fine, and separated with the secun- 
dine, the mouth of which seemed to embrace it firmly: a 
central cavity is evident, the parietes of which are distinct 
towards the apex, more and more indistinct as we approach 
the base : the embryo is visible in the shape of a circular 
vesicle attached by a much smaller one to the apex of the 
nucleary cavity: the apex of the nucleus is kutipntely papil- 
lose, or rather laxly cellular. 
The membrane passes down the secundine at least as far 
as the apex of the nucleus: it is applied to the wall of the se- 
cundine. It varies in size, sometimes closely resembling a 
boyau, at others being much finer than these elongations. It 
passes down, and is applied to the apex of the nucleus to 
* I have noticed the same in a —— genus, although i in wone, T p 
tration had occurred, in others the 
ted their contents. Yet in these, sections of the placenta immersed in water, 
` gave out abundance of mobile granules similar to those contained in the tubes. 
At the same time the ovula were evidently fecundated. 

