198 
CONTRIBUTIONS TO BOTANY. 
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 emhryo-sac, the produc- 
tion of the emhryo, and the means by which the seed is finally 
perfected. It is dso 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 cei’tainly due 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, 
which his predecessors had not noticed ; but his greatest claim 
to distinction rests upon the nomenclature which he devised 
in order to express the changes observed, which will make 
his name prominent in the annals of embryology. It is, how- 
ever, deeply to be regretted that the more original matter con- 
tributed in that memoir, or rather, his explanations of the facts 
there related, should have laid the foundation of the great error 
in the history of these developments, the fallacy of which I now 
proceed to demonstrate. 
In order that I may be free from the blame of misrepresenting 
this subject, I will here quote from the following authorities the 
doctrines they have severally published. 
Mirbel says (/oc. p. 612) that the anatropal owAe's “ se 
renversent tout entiers, et durant ce mouvement de conversion le 
les Vegrfaux Phanrfogames.” 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 
I’Ovule vegrfale.” Mem. de I’Acad. ix. p. 609 : lu a 1’ Academic 28 Dec. 
1828. Additions dans un 2nd memoire lu 28 Dec. 1829; idem, p. 629. 
planches 1-10. 
