ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
309 
Embryogeny of Salix.* — Mr. C. J. Chamberlain has followed out 
the development of the male and female organs and the process of im- 
pregnation in several American species of Salix. In the development 
of the pollen-grains, the division of the original nucleus into generative 
and pollen-tube nucleus takes place before the breakdown of the tapete. 
There is no dividing w r all between the nuclei, as is the case in Populus. 
The cells of the tapete often contain two nuclei. The embryo-sac 
originates in a hypodermal cell at the apex of the nucellus. There are 
sometimes two or three archesporial cells, but it is rare for more than 
one to develop. The primary tapetal cell usually gives rise to a tier 
of three or four cells, but sometimes does not divide. The first division 
of the primary division of the embryo-sac is transverse. The antipodals 
apparently disappear at a very early period. The synergids have fre- 
quently a strongly developed “ filiform apparatus.” The egg-apparatus 
breaks through the wall of the embryo-sac, and projects into the micro- 
pyle. No tendency to chalazogamy could be detected, the pollen-tubes 
always entering the embryo-sac through the micropyle. The first 
division of the fertilised oosphere is always transverse ; the second 
division is usually longitudinal, but sometimes transverse ; the third is 
at right angles to the second. 
Embryogeny of Conifers.! — Prof. J. M. Coulter publishes notes of 
a number of observations on the impregnation and embryogeny of 
Conifers, among which are the following : — In Pinus Bariksiana there 
was observed, after the entrance of the apex of the pollen-tube into the 
oosphere, a peculiar bulging of the larger (female) in the direction of 
the smaller (male) nucleus, before conjugation. In P. Laricio a single 
embryo is frequently developed at the end of two, or even of four sus- 
pensors; occasionally two embryos at the end of a single suspensor. 
In P. Banksiana it appears to be the rule for the first one or two 
.segmentations to be transverse. 
Pollination by Bats.{— -Mr. J. H. Hart states that the flowers of 
Bauhinia magalandra sp.n., a large tree native of Trinidad, are pollinated 
by the agency of bats. The flower is white and strongly scented, and 
opens only in the evening, when it is visited by several species of bat, 
apparently not in search of the nectar, but of the insects which are 
attracted to the flower by its odour. They alight upon and hold fast to 
the protruded stamens, and appear to attack the erect and recurved 
petals, which are often completely destroyed ; and in so doing carry the 
pollen from the anthers to the stigma. 
Fertilisation of Spring Flowers.§— Mr. J. H. Burrill records the 
results of a long series of observations on the fertilisation of spring 
flowers on the Yorkshire coast, with a careful record of the visiting 
insects observed. As a general result he states that short-tongued flies 
predominate in early spring, and that they visit freely flowers with honey, 
whether hidden or exposed. Some early flowering species appear to 
derive no advantage from this precocity. Thus Cajpsella bursa-pastoris 
* Bot. Gazette, xxiii. (1897) pp. 147-79 (7 pis. and 1 fig.). 
t Bot. Gazette, xxiii. (1897) pp. 40-8 (l pi. and 1 fig.). 
t Bull. Misc. Information R. Bot. Gar, den Trinidad, iii. (1897) No. 10, pp. 30-1. 
§ Jouru. of Bot., xxxv. (1897) pp. 92-9, 138-45, 184-9. 
1897 Y 
