ANIMAL SENSE PERCEPTIONS. 327 



Under the second supposition the mystery of life would be still 

 more behind the veil than at present, natural causation would be 

 even less understood ; things would be fewer and farther away, 

 the smaller non-existent, the larger more superficially appre- 

 ciated. Would nature be the same under such different con- 

 ceptions ? — and yet the sense of sight has been alone considered. 

 With a difference in the sensory organs or sensations of smell, a 

 fetid stink might be appreciated as a sweet odour ; touch may 

 from a similar reason become an unknown and unimagined 

 power, or an imperfectly realized sensation ; from a like cause 

 taste may be so varied as to be outside the nauseous or agreeable 

 experiences; while the sense of hearing might develop a familiarity 

 with sounds of which we are absolutely ignorant, or otherwise prove 

 oblivious to some of our most common perceptions.* Without 

 losing ourselves in metaphysical subtleties as to whether things 

 really exist as cognizable by our sense organs, or whether much 

 of our materialism is not only to a considerable degree a question 

 of sensation, we must at least push that problem beyond our- 

 selves, and estimate it throughout all animal life if we hope to 

 gain any clear ideas of the phenomena of animal colouration, or 

 the more complex conceptions of mimicry or protective resem- 

 blance. For instance, it has been proposed that the striped 

 Tiger finds the protection of " aggressive mimicry " by the 

 blending of its colours, or the assimilation of the same, with the 

 reeds or bamboo clusters in which it hides. This is undoubtedly 

 true so far as our own sense organs or powers of sight are con- 

 cerned ; but do the Antelopes or other animals on which it preys 

 have the same sensations on the matter as ourselves ? Increase 

 the penetrating power of vision, and the differences will be so 

 clearly seen and magnified that the theory falls to the ground ; 

 decrease the same, and the proposition becomes more capable 

 of proof. And yet this is the crucial question ; one we answer 

 by inferences, but one to which we can give no absolute 

 reply. 



Again, what do we know as to the colour perceptions of 



* Cases of atrophy following disease appear to be always attended by a 

 corresponding increase of other organs ; blind animals always possess very 

 strongly developed organs of touch, hearing, and smell." Cf. Weismann, 

 'Lectures on Heredity,' &c., 2nd ed. vol. i. p. 88, 



