Woods : On the Reasoning Powers of Caterpillars. 99 



can be determined from the appearance of tlie caterpillar, although it 

 is probable that the sex is determined at a very early period of its 

 existence. As a rule the female moth is larger in size than the male 

 insect, and it has been observed that a caterpillar of more than 

 ordinary size is almost certain to produce a female insect. There 

 seems, however, absolutely no difference in either the colour or 

 markings of the larvse, and even in those species the females of which 

 are wingless, or have very rudimentary wings, we may rear from two 

 caterpillars identical in appearance a beautiful male insect with richly 

 coloured wings, and a female consisting of nothing but a body and 

 legs, and much more like a harvest bug or a spider, than a moth. 



I have already alluded to the instincts of the caterpillar, but before 

 entering on its jDOwers of reasoning it will be necessary for me to 

 define, as clearly as I am able, what I understand by the terms 

 "instinct" and ^' reason," what constitutes their difference, and what 

 are their limits. 



It is perhaps unnecessary for me to insist that instinct and reason 

 are not different degrees of the same faculty ; yet it is not uncommon 

 to hear the remark that " it is impossible to define where one ends 

 and the other begins." Impossible indeed ! but why ? Because the two 

 faculties, like two parallel lines, seem to run side by side, and there- 

 fore never have met, and never can. It is also not uncommon to hear 

 instinct spoken of as a faculty given to the lower animal creation, to 

 serve in the place of the nobler quality of reason vouchsafed to man 

 alone. But on examination I think we shall be compelled to allow 

 that not only has man a large amount of instinct, which probably 

 lessens in its operations as his reasoning powers develop, but that 

 animals of a lower type,'^ although much more dependent than man 

 upon the faculty of instinct, shew beyond the possibility of question 

 very decided signs of the existence of reasoning power. 



Another seemingly prevalent notion is, that an exception may be 

 drawn in favour of certain^animals — dogs, horses, elephants, parrots, 

 cats, in fact many of those animals most frequently domesticated and 

 associated with man, and whose actions and habits are thus brought 

 prominently into notice. For any such arbitrary distinction I have 

 not been able to find any just cause ; nor am I prepared to admit that 

 .these animals, whose intelligence and sagacity are universally acknow- 

 ledged, have any powers differing, except in degree, from those 

 possessed by the rest of the animal creation. I do not forget that 

 there may be several classes or degrees of instinct, differing widely in 



