Earth-Worms in History. 65 
As worms are not controlled by special instincts in each 
particular case, though possessing a general instinct to plug 
up their burrows, and as chance is excluded, the next most 
probable conclusion is that they try in many ways to draw 
in objects and finally succeed in some one way. It is sur- 
prising, however, that an animal so low in the scale as a 
worm should have the capacity to act in this way, as many 
higher animals have no such capacity, the instincts of the 
latter often being followed in a senseless or purposeless 
manner. 
We can safely infer intelligence, as Mr. Romanes, who 
has specially studied animals, says, only when we see an 
individual profiting by his own experiences. That worms 
are able to judge either before or after having drawn 
an object close to the mouths of their burrows how best 
to drag it in, shows that they must have acquired some 
notion of its general shape. This they probably acquire by 
touching it in many places with the anterior extremity of their 
bodies, which serves them as a tactile organ. Man, even 
when born blind and deaf, shows how perfect the sense of 
touch may become, and if worms, which also come into 
being in the same condition, have the power of acquiring 
some notion, however rude, of the shape of an object and 
their burrows, they deserve, it must seem to every sensible 
mind, to be called intelligent creatures, for they act in such 
a case in nearly the same manner as a man would under 
similar circumstances. That worms, which stand so low in 
the scale of organization, should possess some degree of 
intelligence, will doubtless strike everyone as very improb- 
able. It may be doubted, however, whether we know 
enough about the nervous system of the lower animals to 
justify our natural distrust of such a conclusion. With re- 
gard to the small size of the cerebral ganglia, we would do 
well to remember what a mass of inherited knowledge, with 
some power of adapting means to an end, is crowded into 
the minute brain of a worker ant. 
