12 NATURAL SCIENCE [July 
certain species of Coscinodiscus which are abundant at one season, 
disappear later in the year. . 
PLANTS AND THE WEATHER 
WE have received an interesting little pamphlet on the effects of 
weather upon vegetation, the subject of a recent lecture to the 
Bradford Naturalists’ Society. 
The lecturer, Mr John Clayton, has made some simple but none 
the less instructive experiments, the results of which he put before 
his audience. The effects of sunshine are, as we should expect, very 
striking. Of twelve bean-plants, as like as possible in size and 
health, six were placed in the ground where they would catch all 
the sunshine of the day; the other six were sheltered by a boarding 
which effectually prevented any rays from falling upon them. When 
freshly gathered in October the weight of beans and pods grown in 
sunshine was more than three times as great as in the case of those 
grown in the shade (99:29), while the weight of the dry beans was 
in a similar proportion (16:5). The experiment was continued in 
succeeding years. Thus in 1892 the fresh weight of beans and pods 
grown from the sunshine-grown seed of 1891 was half as much again, 
as in the case of plants from shade-grown seeds—all being grown in 
sunshine and under precisely similar conditions in the second year. 
In the fourth year plants with an exclusively shady ancestry produced 
flowers, but failed to mature fruit. 
A series of measurements illustrating the contraction of trees in 
frost was made in the winter of 1894-5. A comparison of the 
girth of tree-trunks in October, when growth had ceased but before 
the frost set in, with the girth at 9 am. on February 8th, at a 
temperature of 3° F., showed an appreciable contraction under frost. 
In the sycamore it was from two to three sixteenths of an inch, in 
the elm from three to five sixteenths, in the oak from five to six 
sixteenths. On March 2, at a temperature of 39° F., the trunks had 
expanded to their original measurements. To this contraction under 
frost is due the frequent splitting of our forest trees. 
An interesting review is also given of the distribution of sunshine, 
rain, &c., in the different months of the year; and various improve- 
ments are suggested for individual months, which we recommend to 
the consideration of the clerk of the weather. 
PLANT CHEMISTRY 
THE chemistry of some common plants is discussed by Dr P. Q. 
Keegan in a recent number of The Naturalist. The buttercup owes 
