CHAPTER V. 



OBSERVATIONS ON YOUNG MAMMALS. 



THE most systematic observations on young mammals with 

 which I am acquainted are those of Dr. Wesley Mills.* They 

 deal with the sensory endowments, instinctive activities, 

 the early habits of the dog, pure-bred and mongrel, the 

 cat, the rabbit, and the guinea-pig; and are recorded in 

 the form of diaries, to which comparisons of the results 

 obtained are appended, and from which conclusions are 

 drawn and clearly set forth. The observations on the guinea- 

 pig supplement and extend those of Prof. Preyer published 

 in his work on the " Mind of the Child. "f Spalding con- 

 tributed to the British Association in 1875 a paper t in 

 which he described a few observations on young pigs. 

 And Mr. W. H. Hudson has recorded some interesting 

 observations on the sheep and deer of South America. 



Just as the young of different kinds of birds are hatched 

 out at different stages of development the megapode 

 being able to fly shortly after birth, and the domestic chick 

 emerging from the shell in a far more advanced stage of 

 development than the pigeon or the rook so is it with 

 mammals. Not to do more than mention monotremes, like 

 the duck-bill (Ornithorhyncus) that lays eggs from which 



* Trans. Roy. Soc. Canada, sect. iv. (1894), pp. 31-62 ; and 2nd series 

 sect. iv.(1895-G), pp. 191-252. 



t Part i., " The Senses and the Will." Eng. trans, by H. W. Brown. 

 New York, 1893. 



J " Habit and Acquisition." See Nature, vol. xii. p. 507. 



" The Naturalist in La Plata," chap. vi. 



