ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 311 



BOTANY. 



GENERAL, 



Including the Anatomy and Physiology of Seed Plants. 



Structure and Development. 

 Reproductive. 



Ovary of Ephedra.* — 0. Lignier and Adr. Toison contribute a note 

 dealing with the ovary and ovule of Ephedra. The authors find that 

 the flovrer is of the angiospermic type, and has a terminal, tetracarpellary, 

 unilocular ovary with a style and basal placentation. In the lower part 

 of the ovary is "a single upright ovule apparently reduced to the 

 nucellus." The fibro-vascular system of the ovule is composed of 

 (1) placental bundles similar to those found in the base of an angio- 

 spermic ovary having basal placentation ; (2) funicular and chalazal 

 branches similar to those which spread over the base of the ovules of 

 angiosperms. Rudimentary vestiges of the integuments can also be 

 traced around the base of the nucellus. The latter has a pollen- 

 chamber, and secretes an attractive fluid which penetrates into the style 

 and issues out at the stigma. The present work, taken in connexion with 

 that done on Welivitschia, leads the authors to conclude that these two 

 genera are very primitive and specialized angiosperms, which have 

 preserved some distinct gymnospermic characters. 



Embryology of the Cruciferse.t— R. Soueges has studied the de- 

 velopment of the embryo of the Crucifer^ in order to clear up some 

 points which have not yet been satisfactorily explained. The author 

 has studied LepkUmn sativum, L. campestre, L. Draba, and Cochlearia 

 officinalis, and finds that the process of development is similar in all 

 four species. The apical cell of the pro-embryo gives rise to the 

 embryo, while from the upper suspensor-cell is formed the hypophysis, 

 which in turn furnishes the initial-cells of tlie cortex and the greater 

 part of the root-cap. The quadrants are formed in two stages ; by their 

 transverse division they become separated into a cotyledonary and a 

 hypocotyledonary region, each composed of four octants. In both 

 regions the epidermis is first differentiated by a wall parallel to the 

 surface. In the lower octant the cortex is developed subsequent to the 

 formation of two rectangular walls, formed at right angles to those of 

 the meridian ; three cells are thus formed, the central of which gives 

 rise to the plerome, and the remaining two to the periblem. "In the 



* Comptes Rendus, clxii. (1916) pp. 79-81. 



t Ann. Sci. Nat. Bot., xix. (1914) pp. .311-39 (73 figs.). 



