218 Mr. A. Henfrcy on Vegetable Emhryogeny, 



last year, but did not reach me until late in the spring of this 

 year, and were therefore overlooked in the brief summary of late 

 researches contained in my last publication. This publication, a 

 paper read before the Linnsean Society of London, March 4th, 

 1856, and reported in the 'Annals' of May following, con- 

 tained the facts supporting, and the more definite assertion of, 

 the opinion which I had propounded in the article '' Ovule " 

 (page 482) in the ' Micrographic Dictionary,' in the autumn of 

 1855, that the germinal vesicles (or corpuscles) exist in the 

 embryo-sac before fecundation, not as complete cells, but as cor- 

 puscles of protoplasm which acquire their cellulose coat after the 

 fertilization hy the agency of the pollen-tube. 



Entertaining this view, it was with no little satisfaction that 

 I last week received a new paper, by Schacht (published in 

 the Reports of the Berlin Academy for May 22nd of this 

 year), on the " Process of Fertilization in Gladiolus segetum/' 

 in which he completely abandons the opinion so long and so 

 warmly urged by him, of the origin of the embryo from the 

 end of the pollen-tube, and not only admits the pre-existence 

 of the embryonal corpuscles, but, in ignorance of my recently 

 promulgated statements, describes the phsenomena nearly in 

 the same manner as I have done in Santalum, more parti- 

 cularly as regards the formation of the cellulose coat around 

 the protoplasmic embryonal corpuscle, as a consequence of the 

 fertilization. This corroboration of my views may be given in 

 his own words : ^' In the unfertilized embryo- sac of Gladiolus 

 segetum lie two germ-corpuscles, closely adherent to the micro- 

 pyle-canal, the upper part of the corpuscles consisting of a 

 bundle of delicate filaments, the lower of a mass of proto- 

 plasm. At the epoch of flowering these corpuscles are not sur- 

 rounded by a firm membrane ; their points project freely out of 

 the embryo-sac. On the third or fourth day after the appli- 

 cation of the pollen, the pollen-tube arrives at the germ-cor- 

 puscles and becomes intimately connected with them, and a firm 

 membrane is developed around the latter as the first product of 

 this conjunction. The end of the pollen-tube swells, becomes 

 thickened, and loses its granular contents. Both corpuscles are 

 ordinarily fertilized by one pollen-tube, but only one of them 

 becomes further developed, a nucleus appearing in its plasma- 

 mass, and soon after this a horizontal septum. The first cell 

 of the rudimentary germ produced in this way grows gradually 

 up into the embryo, while the upper half of the original ger- 

 minal corpuscle becomes the suspensor, which appears firmly 

 connected with the wall of the embryo-sac. Not uncommonly 

 two or three pollen-tubes descend, without producing any essen- 

 tial alterations ; the pollen-tube sometimes branches in the 



