29 
ANT-SUPPORTING PLANTS. 
Br JAMES BRITTEN, E.L.S., 
BOTANICAL DEPARTMENT, BRITISH MUSEUM. 
[PLATE CXVTIL] 
T HE relations between the animal and vegetable worlds, and 
the mutual dependence of one upon the other, offer some 
of the most interesting problems in natural science. The sub- 
ject is one which has attracted special attention of late years, 
and the numerous observations of competent and trustworthy 
persons have rendered us familiar with many striking illustra- 
tions of it. The absolute dependence of certain plants upon 
particular insects for their fertilisation has been amply demon- 
strated ; and it is now shown that insects may, in certain cases, 
serve the requirements of plants in another way, by supplying 
them with food. And this dependence extends more widely 
than might at first sight appear. Mr. Darwin gives an instance 
of this when speaking of the fertilisation of the red clover by 
the visits of the humble-bee. t£ The number of humble-bees in 
any district depends in a great degree on the number of field- 
mice, which destroy their combs and nests ; . . . the number 
of mice is largely dependent, as every one knows, on the number 
of cats Hence, it is quite credible that the presence of 
a feline animal in large numbers in a district might determine, 
through the intervention first of mice and then of bees, the 
frequency of certain flowers in that district.” * 
It is not, however, only as fertilisers or as food-suppliers that 
insects are connected with plants. Botanists are well ac- 
quainted with the fact that certain trees and plants offer homes 
to various species of ants ; but this is not very generally known, 
and, so far as I am aware, no attempt has been made to bring 
together what has been recorded on the subject in scattered 
papers, or to collect the references, often merely incidental, 
* u Origin of Species,” ed. i. p. 74. 
