^be Mbalee. 



THIRTEENTH ORDER: Cetacea. 



HALES are among the 

 mammals what the fish 

 are among the vertebrates: 

 creatures belonging exclu- 

 sively to the water and an- 

 atomically constructed in 

 accordance with the neces- 

 sities of such a mode of 

 life. Their size is an indi- 

 cation of this: for the water 

 alone admits of the easy 

 progress of such giants, 

 and only the infinite abun- 

 dance of the sea affords 

 them the required nourishment. 



The Whales exhibit the warm blood, the breath- 

 ing through the kmgs, the suckling of the 'young 

 and all other essential features of the mammalia, 

 along with the other orders of the class. In every 

 other respect, however, they deviate from the higher 

 mammalia still more than do the Sirenia. Slightly 

 educated persons, and nations in the childhood of 

 civilization, have invariably classed them among the 

 fishes, and only the close modern investigation of 

 their character has assigned them their proper place. 

 General Descrip- The body of the Whales is bulky, 

 tion of the clumsy, and devoid of any external 

 Whales. joints. The head is frequently mon- 



strously large and as a rule unsymmetrical, and 

 merges into the trunk of the body without distinct 

 demarcation of a neck region; the trunk tapers 

 backwards, and terminates in a broad, horizontal 

 tail-fin. The hinder limbs, which distinguish all 

 other mammalia, with the exception of the Sirenia, 

 are absent; the fore pair have become fins: one has 

 to examine these with the dissecting knife, if he 

 wishes to discover the digits in them, and even then 

 he finds peculiarities of structure. An occasional 

 dorsal fin, which extends along the spine, still fur- 

 ther increases the resemblance of these animals to 

 fish. Otherwise the Whales are characterized exter- 

 nally by the wide-gaping mouth, devoid of lips, 

 and provided-either with an abnormally large number 

 of teeth or barbs; by the thin, smooth, soft, greasy- 

 feeling skin, velvety to the touch, and scantily over- 

 grown with bristles in a few small spots. The color 

 is sombre, and the skin contains a thick layer of fat, 

 the entire integument forming a strikingly thickened 

 hide, between the cells of which the fat is deposited. 

 The Anatomical The inner anatomical structure of 

 Structure of these giants of the sea also exhibits 

 Whales. peculiar features. The bones of the 

 skeleton are distinguished by their loose, porous 

 formation, and they are so pervaded by a fluid fat, 

 that the liquid can hardly be eradicated and they 

 preserve a fatty, yellowish appearance even after 

 prolonged bleaching; on the other hand no bone 

 contains a cavity for marrow. The huge skull bears 



a regular proportion to the body in a few species 

 only; the bones of the head are found in queer 

 malpositions : put loosely together if articulated, 

 or are connected with other bones only by soft 

 cartilage; some of them appear stunted, others strik- 

 ingly enlarged and there seems to be no vestige 

 of order or regularity. In the vertebral column the 

 formation of the neck part is most striking. The 

 number of the individual vertebrse is normal, seven, 

 but they are similar in shape to thin, flat rings and 

 not infrequently are partly ankylosed or fused to- 

 gether, producing, in consequence, the little mobility 

 characteristic of the necks of such species as possess 

 this formation- of the cervical region. It is owing 

 to this fact that one often recognizes the seven 

 articulations only by the foramina or apertures in 

 the bony substance through which the pairs of 

 nerves emerge from the spinal cord. Besides the 

 cervical vertebrae the Whales possess from eleven to 

 fourteen dorsal, from ten to twenty-four lumbar and 

 from twenty-two to twenty-four caudal vertebrae. 

 It must be remarked, however, that strictly speak- 

 ing, one may talk only of pectoral or dorsal verte- 

 brae, and of lumbar-caudal ones, as a developed 

 pelvis is absent and no sacral bone exists. The 

 number of true ribs is very small; the true Whales 

 have only one, and more than six do not seem to 

 occur in any member of the order. False ribs al- 

 ways occur in greater number than true ones. The 

 fore limbs are characterized by their shortness and 

 the flatness of all bones, and the strikingly great 

 number of joints in the digits; for while other mam- 

 mals have three joints in the phalanges all Whales 

 have more, with the exception of the first and some- 

 times of the fifth phalange, and the number of 

 joints in one phalange rriay rise to thirteen. 



The dentition of the Whales not only differs from 

 that of all other mammalia but also materially di- 

 verges between the two main divisions of the order. 

 According to Carus, teeth germs form in longitu- 

 dinal pits of the mucous membrane of the jaw in all 

 Whales, but they do not develop into permanent 

 teeth, which are not shed,, except in the case of the 

 Toothed Whales. They disappear in the Whalebone 

 Whales and in their stead there develops an arma- 

 ment of the upper jaw and of the palate peculiar 

 to these animals. In transverse furrows there are 

 formed horny plates or laminae -suspended by one 

 edge perpendicularly to the plane of the cavity of 

 the mouth; the outer ones, fastened to'the upper jaw, 

 are the longest, those on the palate the shortest; 

 they are the baleen, which forms whalebone. 



The epiglottis is not adapted for producing a har- 

 monious voice, but for the passage of a great quantity 

 of air at once. The windpipe is very wide, the 

 lungs have considerable capacity, and all branches of 

 the bronchial tubes communicate with one another, 

 so that from either one both lungs may be filled. 



(559) 



