and its relation to that in the Animal Kingdom, 361 



lopment and present state of the question — I here add what I have 

 learnt since from new works or from such as I had not then access to. 

 For acquaintance with part of these I am indebted to Dr. Caspary. 

 [The older literature here alluded to will be found for the most part 

 included in the list of works appended to a Report by the translator 

 on this subject, printed in the * Annals/ 2nd ser. ix. p. 458. — A.H.] 



An essay of Mirbel and Spach on Zea Mays (* Notes pour servir 

 a I'histoire de I'Embryoge'nie vegetale.' Ann. des Sc. nat. 2 ser. xi. 

 p. 200, 1839 ; and 'Rectification d'un erreur,' &c., id, op. pp. 381, 

 382), is very far from hitting the decisive points. 



Wilson's Researches on Tropceolum majus (Hooker's London 

 Journal of Botany, ii. p. 623, 1843) do not go back to the epoch of 

 the actual origin of the embryo. 



Trecul ('Recherches sur Nuphar lutea' Ann. des Sc. nat. 3 se'r. 

 iv. p. 328, 1845), according to his description, saw the pollen-tube 

 in the micropyle canal, but regarded it as a *' coagulated stream of 

 fovilla," and he left it undecided whether the embryo seen in con- 

 nexion with this "proceeded from the fovilla," or whether " the ovule 

 also contributed a few granules" to its formation. 



Dickie (Ann. Nat. Hist.ser.l.xvii.p.5,1846,&ser.2.i.p.260,1848) 

 wandered from the right path. He, like Brongniart previously, took 

 the end of the pollen-tube projecting from the micropyle for a process 

 belonging to the nucleus (Narthecimii) or the embryo-sac {Euphrasia)^ 

 ending blindly outside (ovule-tube) ; the suspensor he thought was a 

 continuation of this, and the point of the embryo- sac perforated ; and 

 he did not explain the connexion of the embryonal body with the end 

 of the suspensor. According to his own view, he could not find the 

 j)ollen-tube. Independently of these observations, his reasonings 

 inclined to Schleiden's theory. 



Gasparini (Ann. des Sc. nat. 3 ser. xi. p. 365, 1849), continuing 

 his earlier publications, gave some very imperfect researches, deviating 

 fa? from the facts, on the supposed formation of an embryo without 

 the influence of the pollen, in Figs. 



Cobbold (' Embryology of Orchis, Gesneriay &c. Ann. Nat. Hist. 

 ser. 2. X. p. 238. London, 1852 ; written in the summer of 1849) 

 found in the embryo-sac before fecundation " one or more cytoblasts 

 or embryonal vesicles," and believed that the embryo was formed 

 either through the metamorphosis of one of these pre-existing " ger- 

 minal or embryonal vesicles," under the dynamic influence of the 

 fovilla, or, as appeared to him more probable, through the union of 

 the contents of the pollen-tube with those of a germinal vesicle, 

 which process he compared with the conjugation of the Algae. 



A. Henfrey (* Orchis Morio,* Linnsean Trans, xxi. p. 7. Read 

 April 3, 1849) found ordinarily three germinal vesicles in the uu- 

 fecundated embryo -sac ; usually one, more rarely two of them were 

 converted into embryos after fecundation by the pollen-tubes, which 

 mostly travelled down a little distance on the side of the embryo-sac. 

 His researches are accompanied by more detailed drawings than those 

 of his predecessors in the examination of the same plant. 



Sanderson {* liippuris vulgaris^'' Ann. Nat. Hist. ser. 2, v. p. 259, 



