232 
confuse and probably followed with results similar to 
those foreseen by the poet. 
“ The centipede was happy, till 
One day the toad, in fun, 
Said, ‘Pray which leg goes after which?’ 
This strained his mind to such a pitch, 
He lay distracted in a ditch, 
Considering how to run.” 
In these and kindred cases, it would be well for us to 
bear in mind the suggestive remark of Sir John Lubbock, 
characterised by equal modesty and justice, who says, 
in the introduction to his Ants, Bees and Wasps, “ I am 
fully conscious that experiments conducted as mine have 
been leave much to be desired, and are scarcely fair upon 
the ants.”* Both these sources of possible error are 
illustrated in the following case :— 
“ There is a caterpillar that makes a very complicated hammock, 
the construction of which may be divided into six stages. One of 
these caterpillars, which had completed its own hammock, having 
been transferred to another carried only to its third stage, completed 
this also by re-performing the fourth, fifth and sixth stages. But 
another caterpillar, taken out of a hammock which had been only 
carried to its third stage and put into one already completed, 
appeared much embarrassed and seemed forced to go back to the 
point at which it had itself left off, executing anew the fourth, 
fifth and sixth stages which had been already wrought out.”— 
(Dr. Carpenter. Mental Physiology, p. 61.) 
The explanation of the above case no doubt is, that one 
caterpillar was more intelligent than another, but that 
the possibly less intelligent was “ much embarrassed ” by 
a condition of things which could not possibly have oc 
curred in nature. 
(2) In the next place, it is supposed by some that the 
evolution of instincts may take place before intelligence 
makes its appearance, either in the race before it has 
Preface, p. viii.