14 NATURAL SCIENCE [July 
On WILLOWS 
Tue March number of the Botanical Gazette opens with a useful 
paper by C. J. Chamberlain, entitled “Contribution to the life 
history of Salix.” The author has worked out the development of 
the flower, and that of the microspores and macrospores, and their 
germination, the process of fertilisation, and the embryology in 
several species of willows growing in the northern United States. 
In view of the results of the work of Treub, Nawaschin, and 
Miss Benson, on Caswarina and various genera of the so-called 
Amentiferae, considerable interest attaches to Mr Chamberlain’s 
researches. _ 
He finds that Saliz shows none of those striking divergences 
from the usual course of events in the ovule, which have been 
demonstrated in the above-mentioned genera, and his results con- 
firm previous views as to the primitive simplicity of the willow 
flower. A diligent search in buds, both of the male and female 
flowers, failed to reveal the slightest trace of a rudimentary perianth, 
such as might be expected were the floral simplicity the result of 
reduction. The path of the pollen-tube is perfectly normal, an 
entrance to the ovule being effected through the micropyle. The 
synergids have a strongly developed beak, and breaking through 
the embryo-sac, project into the micropyle and attract the 
pollen-tube. | 
Great difficulty was experienced in finding the antipodal cells 
in the embryo-sac; only in six cases out of several hundreds examined 
were they clearly seen. This leads the author to suggest that their 
reputed absence in Caswarina may be due to a similar difficulty. 
The course of cell-division, in the development of the embryo from 
the fertilised ovum, shows several differences in detail from that 
described by Hanstein for Capsella. 
Some interesting sports were also noted. Besides the well- 
known mixed catkins, which were observed in considerable number 
on a vigorous plant of S. glaucophylla in three successive seasons, 
the writer describes and figures the growth of stamens inside the 
ovary, an occurrence hitherto unknown in Salix. These intra- 
ovarian stamens consisted generally of a one-celled stalked or sessile 
anther, borne on the wall of the carpel or on a placenta-like out- 
growth. Occasionally these ambisporangiate ovaries had a perfectly 
natural appearance, but generally they were more or less deformed, 
The ovules were generally inverted (anatropous), their normal form ; 
but occasionally upright (orthotropous) ovules were found, sometimes 
borne on a long stalk. Quite normal embryo-sacs and embryos were 
produced in these sporting pistils. Masters in his “ Teratology” 
mentions only one authenticated case of the formation of stamens 
