of the Vegetable Ovule. 13 



It is important to observe, that the late Mr. R. Brown, to 

 whom science is so greatly indebted for his grand discoveries on 

 this subject, and who in simple language first explained the 

 nature of the changes that take place in the development of the 

 ovule*, does not describe the mode of action objectionably assumed 

 in the writings of physiological botanists ; and it is worthy of 

 remark that he never adopted the nomenclature founded upon 

 the doctrine here alluded tof. 



To Brongniart, who pursued these great discoveries, the highest 

 merit is due for his able and patient investigation J into the 

 nature of the pollen, the peculiar structure of the stigmatic tis- 

 sues, the mode in which the pollinic influence is conveyed into 

 the ovary, the structure of the ovule, of its proper tunics, and 

 of the nucleus, the development of the embryo-sac, the produc- 

 tion of the embryo, and the means by which the seed is finally 

 perfected. It is also deserving of notice, that in all these careful 

 investigations, no allusion is anywhere made to the inversion 

 of the nucleus, or to any excentric growth of the original tunics 

 that might effect the kind of inversion since assumed to take 

 place in an anatropal ovule. It is true that both he and Mr. 

 Brown commenced their researches upon the ovule from the 

 moment it is ready to receive the pollinic influence ; but had 

 either of these careful observers witnessed any such previous 

 action of growth, they would not have failed to allude to the 

 subject. 



Mirbel, who confirmed and extended these interesting re- 

 searches in his celebrated memoir on the development of the 

 ovule §, has received the highest eulogiums from all quarters, 

 for the benefit which these discoveries rendered to science ; but 

 it appears to me that the greatest share of this merit is due to 

 Brown and Brongniart, who preceded him in these inquiries. 

 Much praise is certainly clue to Mirbel for the lucid manner in 

 which he repeated and confirmed the facts already brought to 

 light by those who preceded him, and also for tracing the growth 

 of the nucleus and ovular coats from their first appearance, 



* Appendix to King's Voyage, p. 43. 



t The way in which Mr. Brown uses the term inverted is in a compara- 

 tive sense : loc. cit. p. 52, where he says, " the inner memhrane is inverted 

 with respect to the external umbilicus," or, in other words, that the cha- 

 laza is opposed to the hilum ; but he does not allude to any action of 

 inversion of the ovular tunics. 



% " Memoire sur la Generation et le Developpement de l'Embryon dans 

 les Vegetaux Phanerogames." Ann. Sc. Nat. xii. pp. 14, 145, 225, tab. 34 

 — 44 : read before the Academy, Dec. 28, 1826. 



§ "Nouvelles Recherches sur la Structure et les Developpemens de 

 l'Ovule vegetale." Mem. de l'Acad. ix. p. 609 : lu a l'Academie 28 Dec. 

 1828. Additions dans un 2nd memoire lu 28 Dec. 1829; idem, p. 629. 

 planches 1-10. 



