126 Linnean Society. [Feb. 15, 



radicle and plumule in corresponding depressions of their opposed 

 surfaces. The subsequent changes consist chiefly in the great de- 

 velopment of the cotyledons, which ultimately occupy the entire ca- 

 vity of the nucleus, filling the space usually taken up by albumen. 



From these observ^ations Dr. Giraud deduces the follow^ing in- 

 ferences. 



The formation of the embryo-sac and the development of cyto- 

 blasts vsdthin it having been shown to take place at a period prior to 

 impregnation, and even the primary utricle itself making its appear- 

 ance before the emission of the pollen from the anther and before 

 the expansion of the stigma, the origin of the primary utricle cannot 

 be referred to the influence of impregnation, nor can it have been de- 

 rived from the pollen tube pressing before it a fold of the embryo-sac. 



The primary utricle at its first formation being quite distinct from 

 the embryo-sac, even at its apex (although brought into contact with 

 it at a subsequent period, and ultimately penetrating it), cannot re- 

 sult from a depression or involution of the embryo-sac, as is main- 

 tained by M. Brongniart. 



The pollen tubes (which after impregnation may be traced in the 

 conducting tissue of the style) never reaching the micropyle, but 

 pollen granules being found in abundance in the channel leading to 

 it, and being doubtless brought into contact with the outer surface 

 of the embryo-sac through the exostome ; and the first trace of the 

 embryo appearing at this time in the formation of the spherical body 

 at the inferior extremity of the primary utricle — Dr. Giraud is led 

 to conclude that the origin of this simple spherical body results from 

 a peculiar process of nutrition, determined by the material or dyna- 

 mic influence of the fovilla, conveyed through the medium of the 

 primary utricle or suspensor. 



The paper was accompanied by a series of drawings representing 

 the ovulum of Tropaolum in the several stages of development de- 

 scribed. 



February 15. 



R. Brown, Esq., V.P., in the Chair. 



The Meeting having been specially summoned for the election of 



a Clerk, Librarian, and Housekeeper in the place of Professor Don, 



the Vice-President in the Chair opened the business of the day, and 



the Members present proceeded to ballot. 



