THE ZOOLOGIST 



No. 731. —May, 1902. 



BIOLOGICAL SUGGESTIONS. 



ANIMAL SENSE PERCEPTIONS. 



By W. L. Distant. 



(Continued from vol. v. p. 338.) 



When we undertake the consideration of nauseous or offen- 

 sive smells as means of protection in the animal world, we are 

 able, in some degree, to leave the region of hypothesis which 

 environed us when discussing the question of similarity in 

 sensory impressions in animal vision, and to arrive at negative 

 evidence as to the universality of the sensations of smell. This 

 question becomes most important in estimating the amount of 

 protection afforded to animals by the possession of nauseous or 

 offensive odours. It is unnecessary to recapitulate the many 

 instances already recorded of this protective factor in the struggle 

 for existence. It will suffice to mention, as examples of the 

 phenomena, the immunity from attack possessed by the evil- 

 smelling Skunk (Mephitis mephitica) in the Mammalia, and by 

 the Danaince, Acrcei7ice, and Heliconinte among butterflies, in the 

 possession of malodorous juices that can be exuded from the 

 body. It is more than probable that this offensive attribute is 

 much more prevalent than at present recorded : at the same 

 time, to prove its efficacy, it is necessary to also establish some 

 standard of appreciative nastiness in the smell-impressions of 

 the animal world.* Some animals possess a musky odour, 



* Mr. Beddard considers : — >" Speaking broadly, it is safe to say that the 

 sense of smell is much more highly developed in animals than the sense of 

 sight" ('Animal Coloration,' 2nd edit. p. 177). 



Zool. 4th ser. vol. VI., May, 1902. o 



