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, ' 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 ' 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 cratcegi) which lives in little colonies 

 of ten or twelve in common chambers lined with silk. In 

 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 with 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 killed 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 notation. 



1 Trans. Ent. Soc. France, vol. i., p. 201 . 



2 Introduction to Entomology, Letter xxvi. 



