CHAP. XIV.] ITS NATURE AND ORIGIN. 227 



monotonous note ; and every other animal seems to par- 

 take of the universal joy." * 



The principal Instincts of animals have been grouped by 

 naturalists under three heads : 



1. Those dependent, immediately or remotely, upon incita- 



tions from the Alimentary Canal (e.g., mode of seeking, 

 capture, seizing, storing, or swallowing of food ; and 

 some cases of migration). 



2. Those dependent upon incitations from the Generative 



Organs (e.g., pairing, nidification, oviposition, care of 

 young ; and some cases of migration). 



3. Those dependent upon more general impressions, perhaps 



partly internal and partly external in origin (hyberna- 

 tion and migration). 



These are the classes considered by Kirby and other 

 writers. Those of the first set are often spoken of as 

 Instincts of " self-preservation," and the second as 

 Instincts " devoted to the perpetuation of the species." 

 But language of this kind is apt to be misleading. 

 Animals under the influence of these instincts cannot 

 rightly be supposed to act as a result of reflection, but 

 rather to be at each step (though more or less guided by 

 memory and present sensorial impressions) urged on by a 

 * blind impulse.' Although the successive components of 

 Instinctive Acts for the most part lead to very definite 

 ends, apparent enough to the onlooker, no definite con- 

 ception of the ultimate end to be obtained can be commonly 

 supposed to actuate the animal. 



It is this negative characteristic, indeed, which goes far 

 to explain the essential peculiarity of Instinctive, as opposed 

 to Rational, Acts. Three leading peculiarities of these 

 Acts were given long ago by Dr. W. Alison,! which are as 



* Kirby's " Habits and Instincts of Animals," vol. ii. p. 188. 

 t " Cyclop, of Anat. and PhysioL," vol. iii. p. 4. 



Q 2 



