ANTS —MEMORY. 
39 
Poivers of Memory . 
Little need here be said to prove that ants display 
some powers of memory ; for many of the observations and 
experiments already detailed constitute a sufficient demon- 
stration of the statement that they do. Thus, for instance, 
the general fact that whenever an ant finds her way to a 
store of food or larvae, she will return to it again and again 
in a more or less direct line from her nest, constitutes 
ample proof that the ant remembers the way to the store. 
It is of considerable interest, however, to note that the 
nature of this insect-memory appears to be, as far as it 
goes, precisely identical with that of memory in general. 
Thus, a new fact becomes impressed upon their memory 
by repetition , and the impression is liable to become 
effaced by lapse of time. More evidence on both these 
features of insect-memory will be adduced when we come 
to treat of the intelligence of bees ; but meanwhile it is 
enough to refer to the fact that in his experiments on 
ants, Sir John Lubbock found it necessary to teach the 
insects by a repetition of several lessons their way to 
treasure, if that way was long or unusual. 
With regard to the duration of memory, it does not 
appear that any experiments have been made ; but the 
following observation by Mr. Belt on this point in the case 
of the leaf-cutting ant may here be stated. In June 1859 
he found his garden invaded by these ants, and following 
up their paths he found their nest about a hundred yards 
read another paper before the Linnasan Society, which contains some 
important additional matter concerning the sense of direction in 
ants. It seems that in the experiment above described, the hat-box 
was not provided with a cover or lid, i.e. was not a 4 closed chamber,’ 
and that Sir John now finds the ants to take their bearings from the 
direction in which they observe the light to fail upon them. For in 
the experiment with the uncovered hat-box, if the source of light 
(candle) is moved round together with the rotating table which sup- 
ports the box, the ants continue their way without making compen- 
sating changes in their direction of advance. The same thing happens 
if the hat-box is covered, so as to make of it a dark chamber. Direction 
of light being the source of their information that their ground is being 
moved, we can understand why they do not know that it is being 
moved when it is moved in the direction of their advance, as in the 
experiment with the paper slip. 
