816 



become divided into two cells by a horizontal septum, the upper cell 

 dividing again and growing out through the endostome in a conical 

 form to produce the confervoid filament described by Mr. Brown, and 

 which Mr. Henfrey believes Prof. Schleiden to have mistaken for the 

 pollen-tube. On the 3rd of June, the author again satisfied himself 

 that the vesicle within the embryo-sac (the germinal vesicle) is the 

 first cell of the embryonic body ; it generally exhibits a slight collec- 

 tion of protopalsm at its base, and soon after the pollen-tube reaches 

 the surface of the embryo-sac divides into two cells, the upper divid- 

 ing again and growing into the articulated filament, the cells of which 

 are formed by the production of septa in the same way as in confer- 

 vas, hairs of phanerogamous plants, &c. ; the mucilaginous layer (or 

 primordial utricle of Mohl) being rendered very evident by the appli- 

 cation of iodine. At the same time the lower part of the embryonic 

 body enlarges and soon perfectly fills the embryo-sac, the process of 

 cell-formation by which the embryo is produced varying apparently 

 in different cases. Generally the lowest cell enlarges very much and 

 becomes filled with dark mucilaginous matter, and then this is soon 

 divided into a number of cells by the formation of septa. In some 

 cases two of the germinal vesicles undergo development, and two con- 

 fervoid filaments are produced. 



From these observations Mr. Henfrey concludes that the embryo is 

 really produced by the ovule itself; that the germinal vesicle exists 

 within the embryo-sac before the pollen exerts its influence ; that the 

 pollen-tube penetrates the coats of the ovule to reach the embryo-sac; 

 and that the passage of the pollinic fluid through the intervening 

 membranes impregnates the germinal vesicle, and determines its de- 

 velopment into an embryo. The investigations having been made 

 with every precaution, and the results being in perfect accordance with 

 those of Amici, Mohl, Miiller and others, he believes them to be a 

 sufficient refutation of Schleiden's views so far as the plant in ques- 

 tion is concerned. He regards, however, as points requiring further 

 investigation, the question whether the whole of the pistillary cords 

 are composed of filaments directly produced by the pollen granules ; 

 whether there is any relation between the application of the pollen on 

 the stigma and the development of the germinal vesicles ; and whether 

 the production of the confervoid filaments is a normal process, which 

 is open to doubt when only observed in ovaries containing such an 

 abundance of ovules as those of Orchis Morio. 



