BY THE PRESIDENT. 
3 
whilst the vital organs of the insect are more liable to serious 
injury or even to total destruction. The above considerations tend 
to show that insects require greater protection than plants, and as 
a rule they seem to possess it. 
Many naturalists, and especially Darwin and Belt, have referred 
incidentally to the protection of plants. Wallace has entered upon 
the subject more fully in his i Tropical Nature,’ but the only author 
who has dealt with it in a systematic manner is Kerner.*' The 
arrangement he adopted is different from the one I have chosen. All 
I shall now attempt is to give a few illustrations, mostly observed 
by myself, of various means of protection possessed by plants ; and 
I shall try to render them in that suggestive form which is charac¬ 
teristic of a Presidential Address. We will first consider how far 
protection is obtained by concealment. 
Protection by means of Concealment. 
An object may escape notice in two ways. It may be of the same 
colour as its surroundings, or it may be hidden by being covered. 
Concealment in this latter sense is general in the case of the roots 
of plants, and occasionally occurs with flowers and seed-capsules, to 
which I shall afterwards refer. The leaves of plants are not hidden, 
for the due performance of their function requires exposure to both 
light and air. The function of vegetation in the economy of nature, 
namely, the decomposition of carbonic acid, the absorption of the 
carbon, and the return of the oxygen to the atmosphere, is con¬ 
fined to those portions of a plant which are green. The prevailing 
colour of most plants is therefore green, and when they grow to¬ 
gether it is not easy to distinguish any particular plant, and what 
is not distinguished may easily be passed over. Unripe fruit, which 
is also green, is not readily discriminated from the leaves of the 
tree on which it grows. Where, however, green plants grow 
sparingly on a poor soil, they may easily attract Herbivora in 
search of food. It is true that such animals are generally found 
in places where there is an abundance of pasture, but there may 
be- occasional seasons of drought when verdure is conspicuous, and 
some animals, such as the antelopes, which frequent rocky districts, 
appear to be largely dependent on their sense of sight for finding 
their sustenance. Instances of plants resembling the surrounding 
soil are rare, but they do occur. Thus it is believed that the stone 
mesembryanthemum of the Cape of Good Hope, which is of similar 
* ‘ Die Schutzmittel der Bliithen gegen unberiifene Gaste,’ and ‘ Die Schutz- 
mittel des Pollens, etc.’ A translation of the former is published under the title 
of ‘ Flowers and their Unbidden Guests.’ 
