40 



paper — said that when they had a paper from the lips of one who was an 

 acknowledged master of botanical science, it scarcely became him to invite 

 criticism upon the subject, but he was quite sui-e that so much interest must 

 have been created that there were no doubt many members pi^esent who 

 would like to express their sense of its value. 



Mr. W. H. Gilburt said that the question with which the President had 

 been dealing that night was, perhaps, the most interesting amongst many 

 which occupied the attention of Botanists at the present time, and had 

 given rise to some amount of discussion amongst them. Some of the con- 

 clusions arrived at could scarcely be upset, and| others, possesiring a high 

 degree of probability, were still in abeyance. It had for a long time been 

 held that the Embryo-sac resulted from the simple enlargement of a single 

 cell ; but within the last few months Strasburger and others had shown 

 that a much more complicated process was concerned in its production ; 

 that not only was there an enlargement of a single cell, but also division of 

 the '* Embryo-sac mother cell," and afterward, through the growth of the 

 daughter-cell, which ultimately became the embryo-sac, not only were the 

 Bister-cells, but also the other cells of the nucleus so compressed as to be 

 almost obliterated. They had also long believed that the germinal and 

 antipodal vesicles were produced by free cell formation within the embryo- 

 sac ; but Strasburger had shown that this was not the case, and that they were 

 the results of the division of the protoplasm of the embryo-sac, such divi- 

 sion taking place in the ordinary manner. With regard to the homologies 

 of the ovule, &c., one needed to go carefully through what took place in the 

 higher Cryptogamia and Coniferese and so on to the Phanerogamia, in order 

 to see how one followed up the other. A good example for illustration 

 would be to take the oosphere of the Lycopodiacea and watch the result of 

 fertilisation. The first effect is that the hitherto naked protoplasmic cell 

 becomes clothed with a cellulose wall ; it then divides into two, the lower 

 one of which becomes the embryo the upper one the suspensor. Further 

 division now takes place differently in each of the two cells — in the former, 

 the next two divisions are at right angles to the primary one ; while in the 

 latter all the succeeding divisions are in the same plane as the primary one. 

 In the Phanerogamia the process is in all respects, so far, the same ; while 

 in the Cryptogamia, Ferns, &c., a formation known as the foot is produced 

 from the oospore by division, the remainder developing into the young 

 plant ; the foot being the homologue of the suspensor and the young plant 

 of the embryo. He did not quite understand what the President meant 

 with regard to the relation of the suspensor to the young stem. If he 

 meant that the latter originated fi-om the former, it could not possibly be 

 BO. The embryo which at first is simply a spherical cell, by division pro- 

 duces a mass of tissue which becomes differentiated into several organs, 

 viz., Colyledons and plumule ; while from the lowermost cell of the sus- 

 pensor, or the one next adjoining the embryo, and which is known as the 

 hypophysis, the radicle or young root is developed, the remainder of the 

 Buspcnsor perishing. 



The President said he was very glad they had been favoured with Mr 



