Academy of Sciences in Pans. 347 



in the ' Recueil des Me'moires des Savans Etrangers,' which was 

 ordered by the Academy accordingly. 



Fecundation of the Orchidece and Cisti (Cistinus). On the 1st 

 of August, Messrs. Cassini and Auguste de St. Hilaire made a report 

 on a memoir by M. Adolphe Brogniart on the above subject, of which 

 the following is an abstract. The object of the memoir is to explain, 

 the mode in which the pollen acts on the stigmata, and the manner 

 in which the fecundating fluid passes thence to the ovary in these 

 two families of plants, the reproductive organs of which are not 

 formed in the usual manner, with a view to strengthening the theory 

 formerly promulgated by him as to the general mode of fecundation 

 of plants. The pollen of the orchis is agglomerated in divided and 

 subdivided masses in such manner that the last groups are composed 

 of three, four, or five spherical grains. When these masses fall on 

 the stigma, some of the grains are separated from the rest, and fix 

 themselves on that organ. Each of these grains soon produces a 

 membranous tube, which penetrates into the stigmatic tissue, formed 

 of utriculi, elongated, free, and only united by a viscous liquid. 



In the epipactes, the pollen is pulverulent, formed of small aggre- 

 gations of four spherical grains, which remain always united, and 

 which, when they fall upon the stigma, give birth to very long tubu- 

 lar appendages which penetrate deeply into the stigmatic tissue. 



The ovary of the Orchideae offers internally a simple cavity, having 

 three longitudinal projections, each divided into two laminae ; these 

 are the placentae, which have on their edge an infinity of ovula, so 

 disposed, that the opening through which the fecundating fluid 

 ought, according to M. Brogniart's theory, to reach them, is dia- 

 metrically opposite to the point by which they are attached to the 

 plant. This appeared an astounding objection to the theory, but 

 M. Brogniart explains it thus. The stigmatic tissue is continued in 

 the axis of the column which constitutes the style j it is there, at the 

 summit of the cavity of the ovary, divided into three faisceaux, 

 each of which is subdivided into two filamentary bands, which are 

 applied to the two laminae of each placenta, and as the separate 

 filaments which form these bands are twisted or folded back in 

 festoons, which penetrate between the ovula, and often appear to 

 extend quite to the orifice at their extremity, the stigmatic tissue 

 serves as a conductor to the fecundating fluid, which is thus enabled 

 to attain the orifice at the extremity. The family of the cisti 

 (cistinus) offers, from the ordinary position of the orifice of the 

 ovula, the same objection to the theory of the fecundating fluid 

 proceeding from the stigma to the interior of the ovary by means of 

 that orifice ; but M. Brogniart remarks, that when the orifice of the 

 ovula is opposite to the point of junction with the plant, these ovula 

 are placed on a very long umbilical cord, which is tortuous or bent 

 back, so that the disengaged and open extremity of the ovulum is 

 in contact with the sides of the ovary, of the partitions, or of 



