218 Mr. A. Hcnfrcy an Vegetable Emhryogeny. 



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

 year, and wire therefore overlooked in tlie biief suiiniiiiry of late 

 researches contained in my last ])ublication. This ])ul)heation, a 

 paper read before the Linnocan Society of London, March Ith, 

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

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

 the oj)inion which I had projiounded 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, nut as comjdete cella, but as cor- 

 jtiisc/cs <if protoplfism which acquire their cellulose coat after the 

 fertilization by 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 scgetu7n," 

 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 ])ollcn-tube, and not only admits the ])re-existenee 

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

 ])romulgated statements, describes the phrcnoraena nearly in 

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

 cularly as regards the formation of the cellulose coat around 

 the protoplasmic embiyonal 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 Gladioltis 

 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 j^ee/j/ 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 coi-puscle becomes the suspensor, which appears firmly 

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

 two or three pollen -tube.-* descend, without producing any essen- 

 tial alterations; the pollen-tube sometimes branches in the 



