t they would not hold out so long
as a horse; but they would, undoubtedly, be able to go over the space
in less time. I have frequently beheld this sight, which is capable of
giving one an idea of the prodigious strength of the ostrich, and of
showing what use it might be of, had we but the method of breaking and
managing it as we do the horse."

The following interesting particulars, relating to the capability of
the ostrich to digest hard substances, is given by Mr. Fuller, in his
_Tour of the Turkish Empire_:--"An ostrich, belonging to an English
gentleman, arrived at Cairo from Upper Egypt, and afforded us an
opportunity of observing this curious peculiarity in the natural
history of that animal. The persons in charge of him observing his
great propensity for hard substances, mistook, unfortunately, for his
natural and ordinary diet, things that were only the objects of his
luxury; and while they gave him corn only occasionally, administered
every day a certain portion of iron, chiefly in the form of nails, to
which he occasionally added a knife or a razor, which he chanced to
pick up, or a few loose buttons, which he pulled from the coats of his
attendants. This metallic system did not however succeed; the poor
bird drooped gradually, his strength just lasted him to walk with a
stately step into the court of the Consulate, and he died in about an
hour afterwards. On a _post mortem_ examination, at which I was
present, about three pounds of iron were taken from his stomach. A
considerable portion of the hardest parts, such as the blades of the
knives and razor, was dissolved; and it is possible that the whole
might in time have been digested, as the death of the animal was in
part accidental, being immediately occasioned by a sharp
boat-builder's nail, three or four inches long, which he had
swallowed, and which had penetrated quite through the stomach, and
produced mortification."

W.G.C.

* * * * *

EFFECTS OF LIGHT AND AIR ON PLANTS.

The importance of light and air to plants is well known. When
unassisted by these agents, plants lose their colour, and are deprived
of many of their properties. Colour is thus evidently produced by the
absorption of carbonic acid gas: and the colouring matter may be
detected by a powerful microscope, lodged in the cellular substance of
the leaf. How this colour is formed, and why it assumes different
tints in different plants, are, however,