Mr. A. Ilenfrey on Vegetable Emhryogeny. 217 



XIX. — Recent Discoveries in Vegetable Emhryogeny . By Arthur 

 IIenfrev, F.R.S., Professor of Botany iii King's College, 

 London. 



The subject of the development of the embryo of flowering 

 plants being one of those upon which I have constituted myself 

 a reporter, from time to time, for the pages of the ' Annals,' I 

 find it necessary again to demand a small space, for the purpose 

 of making known some important events which have lately 

 occurred in the history of the Cjuestion, and at the same time of 

 putting in a distinct claim to priority in the publication of one 

 of the most important of the latest discoveries. 



It is well known to all readers of this Journal w^ho are inter- 

 ested in the present subject, that I have always been an advocate 

 for, and defender of, the opinion first put forth by Aniici, that 

 the embryo originates as a distinct cell in the embryo- sac, and 

 is merely fertilized by the pollen-tube. Several ])hysiologists 

 (whose papers will be found referred to in my ' Ileport ' pub- 

 lished in the 'Annals' in 1852*) have argued on the same side ; 

 one of them however, Tulasne, declaring his inability to find the 

 germinal vesicle in the embryo-sac before fertilization, although 

 he distinctly asserts that it originates quite independently of the 

 end of the pollen-tube. On the other hand, Schleidcn has con- 

 tinued to defend his original views, and has been ardently sup- 

 ported by his pupil Schacht, and more lately by Deecke. 



The events of the last few months have quite changed the 

 aspect of the discussion ; not only has Schleidcn given his ad- 

 herence to the opinion that the germinal vesicle pre-exists in the 

 embryo-sac, but Schacht also now states that he was in error, 

 and that the embryo is a product of a body originating in the 

 embryo-sac, and is merely fertilized by the pollen-tube. 



The merit of convincing Schleidcn is due to another of his 

 own pupils, Dr. Radlkofer, of Munich, who published at the 

 beginning of this year some excellent observations on Euphrasia 

 Odontites, and certain other plantsf; and was empowered to 

 make known therein Schleiden's acknowledgement of the accu- 

 racy of his representations. The memoir of Dr. Badlkofer did 

 not add any new fact of importance to our knowledge, but 

 was of much value, not only from its bearing the api)roval of 

 Schleidcn, but from its setting in their true light the phaiuomena 

 which Schacht and Deecke had recently urged as subversive of 

 Amici's views. Dr. Radlkofer's observations were made during 



* Ann. Nat. Hist. Ser. 2. vol. i.\. p. A Jl, &c. 



t Ijic Bcfiuclitunfi tier Phancrof^iimen, von L. Radlkofer, M. & rii.l). 

 Ltipzif^, I85f>. 



