112 Unconscious Memory 



future, and the present gives no ground for conjecturing 

 the time and manner of their subsequent development. 



Secondly, they are manifestly debarred from the category 

 of perceptions perceived through the senses, inasmuch as no 

 information can be derived concerning them except through 

 experience of similar occurrences in time past, and such 

 experience is plainly out of the question. 



It would not affect the argument if, as I think likely, 

 it were to turn out, with the advance of our physiological 

 knowledge, that all the examples of the first case that I 

 am about to adduce reduce themselves to examples of the 

 second, as must be admitted to have already happened 

 in respect of many that I have adduced hitherto. For it 

 is hardly more difficult to conceive of d priori knowledge, 

 disconnected from any impression made upon the senses, 

 than of knowledge which, it is true, does at the present 

 day manifest itself upon the occasion of certain general 

 perceptions, but which can only be supposed to be con- 

 nected with these by means of such a chain of inferences 

 and judiciously applied knowledge as cannot be believed 

 to exist when we have regard to the capacity and organisa- 

 tion of the animal we may be considering. 



An example of the first case is supplied by the larva 

 of the stag-beetle in its endeavour to make itself a con- 

 venient hole in which to become a chrysalis. The female 

 larva digs a hole exactly her own size, but the male makes 

 one as long again as himself, so as to allow for the growth 

 of his horns, which will be about the same length as his 

 body. A knowledge of this circumstance is indispensable 

 if the result achieved is to be considered as due to reflec- 

 tion, yet the actual present of the larva affords it no ground 

 for conjecturing beforehand the condition in which it will 

 presently find itself. 



As regards the second case, ferrets and buzzards fall 

 forthwith upon blind worms or other non-poisonous snakes, 

 and devour them then and there. But they exhibit the 

 greatest caution in laying hold of adders, even though 



