2 3 3 THE POPULAR SCIENCE MONTHLY. 



veritable affinity. A popular lesson in natural history, then, teaches 

 us that a whale is a quadruped that is, apart from the mere etymol- 

 ogy of the word, it belongs to the quadruped class. It possesses but 

 two legs, or rather " arms," it is true, and these members do not re- 

 semble limbs. But it is a quadruped notwithstanding its deficiencies 

 in this respect ; and it agrees in all the characters which are found to 

 distinguish the class to which man himself belongs, that of the Mam- 

 malia. These characters it may be advantageous very briefly to detail, 

 by way of preliminary to the general study of whales and their near- 

 est relations. Thus, firstly, they are warm-blooded animals, a state- 

 ment which must be taken as meaning that their blood is of a temper- 

 ature considerably higher than that of the medium in which they live. 

 The fish, on the other hand, is a cold-blooded creature. Its tempera- 

 ture is only slightly higher than that of the surrounding water, and in 

 this respect it agrees with all invertebrate animals and with the frogs 

 and reptiles of its own sub-kingdom. Next in order may be noticed 

 the agreement of the whale with the quadruped in the matter of body- 

 covering. The covering of the latter consists of hairs. Although the 

 body of the whale can not be described, by any stretch of the imagi- 

 nation, as having hair, the presence of a few bi'istles around the mouth- 

 extremity sufficiently indicates the nature of its outer garment ; while, 

 before birth, the body-covering in some whales is tolerably plentiful, 

 but is soon shed, leaving the hide thick, shining, and hairless. The 

 microscopist might inform us that the blood of the whale presents the 

 same characters as that of other mammals, and possesses red corpuscles 

 or colored bodies, which, unlike those of the fish, reptile, and bird, 

 have no central particle or " nucleus." And while the heart of the fish 

 is a comparatively simple engine of propulsion, consisting of two con- 

 tractile chambers or cavities, the whale's heart will be found like that 

 of man and other quadrupeds in all essential details of its structure. 

 It is thus a four-chambered organ doing double duty, in that it sends 

 blood not only through the system, but also to the lungs for purifi- 

 cation. 



The mention of lungs as the breathing organs of whales at once 

 introduces us to a new field of inquiry concerning the habits and life 

 of the aquatic monsters. A popular notion exists that of necessity a 

 water-living animal must be a water-breather. The idea of fish exist- 

 ence and of the manner in which fishes breathe evidently reigns para- 

 mount in the present case. That an animal may be completely aquatic 

 in its habits, and yet breathe air directly from the atmosphere, and 

 after a like procedure to that witnessed in human respiration, is a no- 

 table fact. A water-newt, despite its aquatic habits, ascends periodi- 

 cally to the surface of the water to breathe ; and seals, walruses, and 

 whales agree in that they are truly lung-breathers, and possess gills at 

 no period of their existence. True, a gill differs from a lung only in 

 that it is capable of exposing the blood circulating through it to the 



