26 
ANIMAL INTELLIGENCE. 
Some evidence of intelligence seems to be displayed 
by the razor-fish. For the animals dislike salt, so that 
when this is sprinkled above their burrows in the sand, 
they come to the surface and quit their habitations. But 
if the animal is once seized when it comes to the surface 
and afterwards allowed to retire into its burrow, no 
amount of salt will force it again to come to the surface . 1 
With regard to snails, L. Agassiz writes : 6 Quiconque 
a eu Foccasion d’observer les amours des limapons, ne 
saurait mettre en doute la seduction deployee dans les 
mouvements et les allures qui preparent et accomplissent 
le double embrassement de ces hermaphrodites . 5 2 
Again, Mr. Darwin’s MS. quotes from Mr. W. White 3 
a curious exhibition of intelligence in a snail, which does 
not seem to have admitted of mal-observation. This 
gentleman 6 fixed a land-shell mouth uppermost in a 
chink of rock ; in a short time the snail protruded itself 
to its utmost length, and, attaching its foot vertically 
above, tried to pull the shell out in a straight line. Not 
succeeding, it rested for a few minutes and then stretched 
out its body on the right side and pulled its utmost, but 
failed. Resting again, it protruded its foot on the left- 
side, pulled with its full force, and freed the shell. This 
exertion of force in three directions, which seems so 
geometrically suitable, must have been intentional . 5 
If it is objected that snail shells must frequently be 
liable to be impeded by obstacles, and therefore that this 
display of manoeuvring on the part of their occupants is to • 
be regarded as a reflex, I may remark that here again we 
have one of those incessantly recurring cases wdiere it is 
difficult to draw the line between intelligence and non- 
intelligence. For, granting that the action is to a certain 
extent mechanical, we must still recognise that the 
animal while executing it must have remembered each of 
the two directions in which it had pulled ineffectually 
before it began to pull in the third direction ; and it is 
improbable that snail shells are so frequently caught in 
positions from which a pull in only one direction will 
1 Bingley, be. cit., vol. iii. p. 449. 
2 De VEspece et de la Clause, &c., 1869, p. 106. 
8 A Londoner's Walk to Edinburgh , p. 155 (1856). 
