Marvels of the Universe Wie: 
plants come into contact with certain animals, and have been seriously modified by the relation- 
ship, that it is no longer possible to regard them as mere automata, or to deny them the possession 
of some glimmerings of sense. The evidence for this unorthodox view is far too voluminous and 
varied to be even hinted at here; but one sample may be given which is only one of many such 
that have been carefully investigated. 
The case we have selected is that of the Bull’s-horn Thorn or Acacia, a plant of the Central 
American savannahs. As in most of the Acacias, the long leaf is broken up into a number of leaflets, 
arranged in pairs along the midrib, and the branches and twigs are protected from the depredations 
of browsing animals by the development of thorns and spines. In the Bull’s-horn Acacia these take 
the form of long, stout curved thorns set in pairs in such relation to each other that they present 
much the appearance of the horns 
of a bull, to which circumstance 
the plant owes its name. But 
like most other vegetation of that 
region, the Acacia has a worse 
foe than the herbivorous mam- 
mal to contend with, and one 
against which the sharpest spines 
are no protection. This is the 
Sauba or Leaf-cutting Ant, con- 
cerning which we gave some par- 
ticulars in the first volume of 
this work. The Sauba comes in 
hundreds, and in a few hours 
completely defoliates the tree or 
bush it has fixed upon for attack, 
carrying the leaves home to con- 
vert into leaf-mould upon which 
to grow fungi for food, being a 
vegetarian ant. 
By some means the Acacia 
has learnt, through the experi- 
ence of its ancestors, that there 
are carnivorous and stinging ants 
as well as herbivorous ants, 
and that the former is the best 
antidote to the latter. If we 
were to judge by results in this 
matter we should have to con- 
fess that the “ insensible ” plant 
has more intelligence than man. 
Man the cultivator can _ only 
see in insects of all kinds active 
enemies, and impartially kills all, 
friends and foes alike. The 
Acacia is more discerning—en- 
courages the friend, pays him for 
his protection and so holds the 
Photo by) [S. ZL Bastin. 
AN AFRICAN ACACIA’S SPINES. 
In this species the spines are much dilated at the base, and used as nests 
foe at bay. by protecting ants 
