ADVERTISEMENT. 



It will occur to many of our Readers that the order 

 of Mammalia, to which the present Volume of the 

 Naturalist's Library is devoted, viz. the Cetacea or 

 the ordinary or fish-like Whales, have some claims 

 to a place in our series. It is true that these tribes 

 have none of those rural charms which are con- 

 nected with our flocks and herds ; and still less can 

 they attract the eye, as do the rich and golden hues 

 which adom the humming-bird and paint the wings 

 of the butterfly ; though it will be found that, even 

 in this respect, they possess a richness and variety 

 not generally supposed. But leaving this; when 

 we consider the singular peculiarities in the consti- 

 tution of Whales, — ^that they are warm-blooded 

 mammalia, that is to say, that they breathe as the 

 terrestrial mammalia, and suckle their young, and 

 yet are as completely aquatic as true fish; and 

 when, moreover, vre reflect that they vary in size 

 &om the dimensions of a salmon to a length of 

 a 



