240 
ANIMAL INTELLIGENCE. 
case. It was observable that the animals were guided neither 
by sight nor smell while endeavouring to close up the inter- 
rupted line ; for the caterpillar next behind the interruption, on 
whom the duty of closing up devolved, 4 turned right and left, 
and often in a wrong direction, when within half an inch of the 
one immediately before him ; when he at last touched the ob- 
ject of his search, the fact was communicated again by signal ; 
and in thirty seconds the whole line was in rapid march/ This 
gentleman adds that the object of the march was the search for 
new pasture. The caterpillars feed on the Eucalyptus, and when 
they have completely stripped one tree of its leaves, they all con- 
gregate on the trunk, and proceed as described to another tree. 
De Villiers 1 gives an account of his observations on the 
manner in which these caterpillars ( Cnethocampii pitzo- 
campa) are able to pass information, which does not quite 
agree with the above observation of Mr. Davis. For he 
says that, in a train of 600 caterpillars, interference by 
him in any part of the train was communicated through 
the whole series instantaneously — all the 600 caterpillars 
stopping immediately and with one consent like a single 
organism. 
According to Kirby and Spence there is a kind of 
caterpillar ( Pieris cratoegi) which lives in little colonies 
of ten or twelve in common chambers lined with silk. 3n 
one part they make of the same material a little bag or 
pocket, which is used by the community or household as 
a water-closet. When full of excrement the caterpillars 
empty it by turning out the pellets wfith their feet. 2 
Only two other instances of noteworthy intelligence 
as exhibited by larvae have fallen within my reading. 
One of these is mentioned by Reaumur, who says that 
the larvae of Hemerobius chrysops chase aphides, and 
having billed them, clothe themselves in their skins ; and 
the other case is the very remarkable one mentioned in 
his newly published work by W, MacLachlan, -F.R.S., of 
caddis- worms adjusting the specific gravity of their tubes 
to suit that of the water in which they live, by attaching 
heavy or light material to them according as they require 
sinking or flotation. 
1 Trans. Ent. Soc . Franco, vol. I, p. 201. 
2 Introdicction to Entomology , Letter xxvi 
