﻿2l8 MELD AND FOREST. 



branchy stinging-hairs, or thorns, lives on mulberry and other trees. 

 Like other caterpillars protected from ememies by odor, stinging- 

 hairs, or otherwise, it sits upon the upperside of the leaves; it is light- 

 colored, the head red, the hairs white. Across its back, between its 

 thorns, there sits a small blackish caterpillar, protecting itself by the 

 thorns of the large companion. I took off the small caterpillar from 

 the large one, but it soon occupied the same place. In order to take 

 a photograph of it the larger caterpillar was anaesthetised with ether; 

 it recovered again somewhat but after two days it died. The smaller 

 caterpillar' has now left its place, and taken refuge on another cater- 

 pillar in the same box; on this it sits, somewhat further forward, on 

 the base of the abdomen. In its former host, the place where the 

 smaller caterpillar sat looks pale, as if it had been scoured. The 

 small caterpillar from above eats holes in the leaf on which the larger 

 one is sitting. As far as I know, no similar case has hitherto "been 

 observed." 



Ingenious microscopic adjustment. — M. Govi in a paper read 

 before the French Academy, February 19th, 1877, describes a very in- 

 genious method of altering the focus of a microscope by interposing 

 between the object and objective a transparent tank that admits of 

 being filled to varying depths with a liquid more refractive than air. 

 By this means a stage micrometer may be used for the measurement of 

 objects without risk of errors arising from imperfect collimation of the 

 various parts of the microscope. It is evident however, that is can 

 only be used with low powers. 



Intelligence of Ants. — The same journal notices a paper lately 

 read by Sir John Lubbock before the Linnaen Society, in which it is 

 stated that the researches of this gentleman do not lead him to think 

 so highly of the intellegence of ants. He states that they had not 

 sense enough to drop from a height of only three-tenths of an inch 

 from the ground, but went a long way round, owing to their want of 

 power of calculating distance. In other respects, however they are 

 intellegent enough, thus they soon recognize their friends, even after 

 a year's separation. Slavery in certain genera is a regular institution. 

 The Amazon ants (Polyergus rufescens) absolutely require a slave to 

 clean, dress and feed them ! Repeated experiments prove that they 

 will rather die then help themselves. 



