29 1 
A THE GEELONG NATURALIST. 
the leaf. They regulate the passage inwards of air, and the 
passage outwards of gases evolved by the leaf; also, of the 
vapour from the water that comes up from the roots, which, 
escaping into the air through these openings, leaves the food 
materials behind. 
(b) The Chlorophyll-tissue—this consists of cells con- 
taining the green coloring substance already mentioned. The 
cells underneath the upper surface of the leaf are longer than 
broad, and the direction of their length is upwards. This is 
the reason why the upper surface of leaves appears greener 
than the under surface. Underneath this ** palisade-layer," 
as it is called, lies a second layer of shorter and less regular 
cells ; near the under surface of the leaf is the spongy layer, 
so called because of its loose arrangement, allowing of large 
air spaces among the cells, which air spaces are in com- 
munication with the very numerous stomata of the under 
surface. It is by this layer that the process of transpiration 
already referred to, is chiefly carried on; it is regulated by 
the opening and closing of the stomata. Each stoma has, 
what is called, a guard cell on each side of it. These guard 
cells contain chlorophyll, and it is supposed that the chemical 
action set up by the chlorophyll under the stimulus of sun- 
light, together with the direct influence of the sunlight upon 
the molecular condition of the protoplasm, bring about the 
opening of the stomata at the proper time, and the closing 
also. 
The great work of the chlorophyll is that of assimilation, 
i.e., taking the Carbon Dioxide that passes into the leaf and 
decomposing it, reserving the Carbon, and giving off the 
Oxygen, and thus with the help of the Oxygen and Hydrogen 
of water manufacturing starch. 
The subject was illustrated by large diagrams prepared by 
the lecturer, also by lantern slides, prepared by Mr. Adcock. 
At the close of the paper the microscope was brought into 
use, and the living cell, chlorphyll tissue, and many other 
portions of the leaf were shown to those present. 
OUR FEATHERED FRIENDS. 
PAPER READ BEFORE THE MEMBERS BY J. F. MULDER. 
Tue title of this paper applies more particularly to the 
insectivorous and carnivorous birds. In the front rank we 
must place the Owl, this bird being an especial friend to the 
farmer. Of our Australian varieties, the Delicate Owl (Strix 
flammea) is the nearest approach to the European Screech or 
Barn Owl. Itis about 15 inches long, and has an expanse 
of wing of 26 or 28 inches. The underneath feathers are 
