ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
763 
Embryo of Trapa, Nelumbium, and of some Guttiferae.* — M. D. 
Clos has studied the germination of the seeds of Trapa natans, and puts 
a different interpretation on the morphology of the various parts from 
those which have hitherto been proposed. He regards the embryo as 
belonging to the group which he terms macropodous. What has hitherto 
been taken for the single large cotyledon is the greatly enlarged hypo- 
cotyl, which always remains inclosed, but emits from below the pericarp 
a straight slender prolongation, 5-8 cm. in length, which becomes 
horizontal and channelled for the insertion of the single cotyledon and 
of the contiguous buds. The embryo of Trapa is, therefore, monocotyle- 
donous and rootless. 
Some species of Guttiferae and Clusiaceae are also characterized by 
macropodous embryos. 
In the ovule of Nelumbium speciosum, the best interpretation of the 
peculiar and difficult points of structure appears to be that the thin 
integument consists of the primine only, aud that the large fleshy body 
below the embryo-sac, which becomes bipartite on germination, is formed 
by the complete concrescence of the secundine with the nucellus. The 
embryo makes its appearance between the two plates into which this 
body divides. 
Fruits which expel their seeds with violence (Schleuder- 
friichte). j — Herr E. Huth enumerates twenty-five families and forty-eight 
genera in which fruits of this description occur. He classifies them 
under three heads, viz. (1) Dry fruits ; in these either the carpels roll 
up when ripe so as to expel the seeds ( Eschscholtzia , Corydalis , Cardamine, 
Viola, Euphorbia, Bicinus, many Leguminosae, &c.), or they belong to 
climbing plants, and are dragged for a short distance by animals by 
means of hooks and bristles, and then spring back suddenly and expel 
the seeds ( Setaria , Lappa , Martynia (?), &c.). (2) Hygroscopic fruits ; 
either dry (Arena), or furnished with elaters ( Jungermannia , Equisetum). 
(3) Succulent fruits, in which the seeds are expelled in consequence of 
a sudden access of water ( Impatiens , Momordica , Elaterium , Dorstenia , 
Oxalis, &c.). In the case of the last-named genus, the mechanism lies 
not in the pericarp, but in a fibrous layer which envelopes the seeds. 
The greatest distance to which the author observed that seeds could be 
expelled was 10 metres in the case of Wistaria sinensis (by night). 
Fruit and Seed of TJmbelliferse.t— Sig. E. Tanfani has continued 
his researches on the morphology and histology of the fruit and seeds of 
the Apiaceae (Umbelliferae). He adopts the view of the morphology of 
the flower supported by Celakovsky, viz. that the inferior ovary is com- 
posed of the concave receptacle, which incloses in its interior the base of 
the carpellary leaves, and bears on its margin the other floral whorls. 
The seed may be either orthospermous or campylospermous, and there 
are all intermediate conditions between the two. The embryo is small and 
straight, and is attached to the summit of the endosperm ; occasionally 
there is only one cotyledon. 
* Bull. Soc. Bot. France, xxxviii. (1891) pp. 271-6. 
t Samml. Naturw. Vortrage, iii. (1890) 23 pp. and 5 figs. See Bot. Centralbl., 
1891, Beih., p. 267. 
X Nuov. Giorn. Bot. Ital., xxiii. (1891) pp. 451-69 (4 pis.). 
3 H 2 
