ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 271 



In a stort time all these nuclei place themselves against the cell-wall ; 

 the protoplasm around them becomes differentiated, and the pro- 

 embryo (suspensor) is formed. This increases laterally and basally, 

 while the upper part of the cavity does not become filled with new 

 tissue. The summit of the suspensor, continuing to grow, elongates, 

 and pierces the membrane of the corpuscule. Three parts can then be 

 distinguished — the embryo properly so called, the suspensor, and 

 the portion which continues to retain the form of a sac. The following 

 stages resemble those of other Gymnosperms, and one only of the 

 embryos arrives at full development in the seed. 



The changes which take place in the ovule of Cycas circinalis, in 

 consequence of impregnation closely resemble those in Ginkgo hiloba 

 {Salisburia adiantif olio), indiic&img an affinity between these two genera. 



Embryo of Barringtonia.* — According to M. Treub, the embryo 

 of Barringtonia Vriesii produces a certain number of small leaves, 

 before its growth is arrested at the summit, at the time of maturity 

 of the fruit. These leaves remain in the condition of scales, and 

 produce minute buds in their axils. During germination this apical 

 portion elongates into a young stem which produces scales and then 

 normal leaves ; when its development is interrupted, one or more of 

 the buds of the embryonal scales develope and replace it. Examined 

 in transverse section, the young embryo shows a thin circular layer of 

 cells which divides the body of the embryo into a cortex and a thick 

 medulla ; this layer being the principal cause of the erroneous in- 

 terpretations to which the embryo of Barringtonia has given rise. At 

 the time of germination a formative fibrovascular layer is formed 

 towards the inner portion of the separating layer ; and a secondary 

 layer is then produced below the liber, and the primary cortex is 

 exfoliated. 



Fertility of Hybrids.f — Eecorded and undisputed cases of 

 sterility in hybrid plants are, T. Meehan states, in fact extremely 

 rare. In most cases it has been assumed that the plants were hybrids 

 because there was some difference in appearance from the normal 

 form, or because they were sterile. In his view there is no reason to 

 believe that there is any more sterility attached to hybrids than to 

 ordinary plants. 



Germination of Flax and Sweet Almond. | — A. Jorissen has deter- 

 mined, by chemical tests, that seeds of flax which have germinated 

 for a short time contain a considerably greater quantity of hydro- 

 cyanic acid than ungerminated seeds, showing that the substance 

 which yields this acid is one of the products of transformation of 

 the nitrogenous constituents during germination. Amygdalin is 

 formed in the process of germination, even in the dark ; and in the 

 sweet almond a substance of similar properties is contained in the 

 plumule and radicle ; in smaller quantities in the cotyledons. Another 

 glucoside, solanin, is also formed during germination; and this 



* Ann. Jard. Bot. Buitenzorg, iv. (1884) pp. 101-8 (1 pi.). See Bull. Soc. 

 ■ Bot. France, xxxi. (1884) Kev. Bibl., p. 77. 

 t Amer. Natural., xix. (1885) pp. 73-5. 

 X Bull. Acad. R. Sci. Belg., vii. (1884). 



