70 PROFESSOR HENFREY ON THE DEVELOPMENT OF THE OVULE 



jiendently of the apex of the pollen-tvibe, this very point is most warmly contested by 

 Schacht*, and notwithstanding that I have tolerably positive opinions derived from a 

 certain niunber of cases, where the end of the poUen-tube and the gernunal vesicle (the 

 summit of the suspcnsor) were seen together, but distinct, in one preparation, the objects 

 are so delicate, and the cause producing obscm-ity of the preparation so difficult to guard 

 against, that I cannot but think the demonstration of the pre-existence of the germinal 

 vesicle in the embryo-sac, the most important fact that can be brought forward in oppo- 

 sition to the views of Schleiden. As remarked by Tulasne, it has a great philosophical 

 importance in reference to speculations as to the source of the vitality of the new being ; 

 and, as will be shown below, it is of no less importance for the establishment of the rela- 

 tions of the processes of embryogeny m the various classes of plants, and of the analogies 

 which these present to phasnomena attending the reproduction of animals. 



As in my former paper I selected one well-established series of observations for the 

 support of the doctriae I advocated, passing over without notice numerous fragmentary 

 researches which, although corroborative, had in themselves nothing absolutely decisive, 

 I shall here confine myself to the course of development of the ovule of one plant, in 

 which the complete series of observations have been repeated many times. I feel the less 

 hesitation in laying before the Society a paper thus restricted, from the circumstance that 

 the example brought forward possesses features of great interest in other respects besides 

 the main point of the fertilization. The principal facts are not indeed now brought for- 

 ward for the first time, even befoi'e this Society, but they are such as few botanists have 

 the opportunity of testing for themselves, and hence may be admitted as supplementary, 

 partly confii'matory, partly emendatory, of the memoirs on the same subject by the late 

 William Griffithf. 



A melancholy interest is attached to the investigations now presented ; for the mate- 

 rials which have enabled me to repeat and control the observations of Griflith, were 

 fm-nished by my lamented friend Dr. Stocks, another Eellow of this Society, suddenly cut 

 off from us in the midst of active labours for the advancement of Indian botany. 



A bottle containing a large quantity of blossoms and fruits of Santalum album, in all 

 stages of growth, preserved in spirit, enabled me to trace the development of the ovules 

 and the embryos from a very early period; the preservation in spii-it seemed rather 

 favourable than otherwise for the dissections required, since the albuminous matters were 

 coagulated, and thus did not run out over the sections, and the cell-membranes seemed to 

 have acquii'ed a firmer consistence than I have usually found in fresh objects. 



When very young buds are examined in vertical sections (Tab. XVII. fig. 1) the ovary 

 is found superior, forming a conical body arising in the centre of the flower ; as the bud 

 advances in age, the adherent tube of the calyx and the side-walls of the ovary grow 

 rapidly (Tab. XVII. figs. 3-5), so as at length to render the ovary altogether inferior 

 (Tab. XVII. fig. 14) ; the original conical summit (continued into the style) becoming 

 graduaUy flattened by the lateral elevation (Tab. XVIII. figs. 22, 27, 28). 



The ovary never exhibits any open cavity; the centre is occupied by an elongated, 



* Flora, 185.';, p. 145; Botanisclie Zeitmig, 1855, p. 641. 

 t Linn. Trans, xviii. pp. 59 & 71 ; six. pp. 171 & 487. 



