

CETACEA. 



CETACEA. 



691 



the cut, towards the top of the head : the same simplicity exists in 

 that of the Cachalots, but it is situated at the upper extremity of 

 the snout. In the Whalebone Whales it is double, opening towards 

 the summit of the head, as in the Dolphins, in a cresoentic form 

 whose convexity is sometimes anterior and sometimes posterior. 



Vertical section, exhibiting the tongue, larynx, and nostrils of the Porpesse. 

 (' Catalogue of the I'hysiolosical Series ' (Mus. Coll. Chir.), vol. ii. pi. 29, p. 163.) 



Uropoietic System. Professor Owen observes, that if we were 

 acquainted with the structure of the urinary organs of the Herbivorous 

 Cetacea, as it is exemplified in the Dugong alone, we should have to 

 establish as marked a distinction in this respect between them and the 

 true Cetacea as in the preceding organic systems. Instead of the 

 numerous and minute lobuli or renules' into which the kidney is sub- 

 divided in the Dolphins and Whales, it presents in the Dugong a 

 simple compact form with an unbroken external surface ; the tubuli 

 uriniferi terminate upon two lateral series of eleven mammilla;, which 

 project into a single elongated cavity or pelvis, from which the ureter 

 is continued. In the Northern Manatee however, Steller, whose 

 accuracy Professor Owen justly notices, describes the kidney as being 

 subdivided like that of the Seal and Sea-Otter. A similar lobulated 

 structure is also ascribed by John Hunter, in his paper on Whales, in 

 ' Phil. Trans.' (1787), to the Manatee, including it, with the Seal and 

 White Bear, among the animals occasionally inhabiting the water. 

 Daubenton, in his anatomical description of the Manalut Americaniu, 

 merely notices the kidneys as oblong, and placed opposite to each 

 other ; nor does his figure give any indication of lobulated structure ; 

 neither does Sir Everard Home mention such structure in his Anatomy 

 of the Manatee in ' PhiL Trans.' (1821). This want of uniformity 

 in the structure of the kidney in the Herbivorous Cetacea is however, 

 Professor Owen adds, of less moment with reference to their natural 

 affinities ; since in the Pachyderms we find some species, as the 

 Rhinoceros, and though in a less degree, the Elephant, presenting a 

 subdivided kidney ; while others, as the Tapir and Hog, have it entire. 



In the foetus of the Dolphin, according to Muller, the lobules of 

 the kidney consist principally of convoluted uriniferous ducts, 

 extending from the apex to the circumference of the lobule ; the 

 intertwining* of the tubuli arc greatest in the intercortical portion. 

 It is a curious fact, Professor Owen remarks, that the supra-renal 

 gland in the Porpesse presents a certain resemblance to the kidney in 

 nlated exterior ; but, he adds, the analogy extends no farther, 

 fr on making a section of this part it was found to consist of the 

 usual continuous compact substance. 



Generative System. John Hunter remarks that the organs of genera- 

 ! this order of animals come in both sexes nearer in form to those 

 of the Ruminants than of any others ; and this similarity is particu- 

 larly remarkable in the female ; in the male their situation varies on 

 account of the modification of the external form of the body. 



The female organs in the Jlytina have been described by Steller ; 

 and Sir Everard Home has given an account of those of the Dugong. 

 ('Phil. Trans.,' 1820.) 



Hunter, in his paper on Whales has entered particularly into the 

 structure of those of the Zoophagous Cetaceans. The period of 

 lifeline gestation does not appear to be certainly known ; the number 

 of young is generally considered not to exceed one, there being but 

 two nipples; the glands for the secretion of milk are two, one on each 

 f the mesial line of the belly at its lower part. The milk is very 

 rich, like that of a cow to which cream has been added. 



Professor Owen remarks, that much stress has been recently laid 

 on the supposed existence which the muscles surrounding the mam- 

 mary gland afford in the act of suckling, by compressing the gland and 

 ;t ting the milk accumulated in the dilated receptacle or reservoir ; 

 Imt he observe* that, considering how great the pressure of the 

 surrounding water must be upon the extended surface of the mam- 

 mary gland, it may readily be conceived, that when the nipple is 

 flTMijMa ly the mouth of the young, and the pressure removed from 

 it by the retraction of the tongue, the milk will be expelled in a 

 copious stream by means of the surrounding pressure alone, indepen- 



dently of muscular aid. The Professor adds, that the intimate struc- 

 ture of the mammary gland in the Zoophagous Cetacea is essentially 

 the same as in the OrnH/iorliyncliut, being composed of an innumerable 

 quantity of coocal tubes ; these are however shorter than in the 

 Ornithorhynchus, and their glandular parietes are firmer ; they ar-e 

 well shown in the figure of the mammary gland in a young Piked 

 Whale (Balcenoptera rostrata) given by Muller in his seventeenth plate, 

 fig. 2., and according to that author present, after the Ornithorhynchta, 

 the simplest structure of the mammary gland in the entire mammi- 

 ferous series of animals. 



Brain, Nervous System, and Senses. The brain is well formed. In 

 the Porpesse and the common Dolphin it has been stated to be as 

 highly developed as in any mammiferous quadruped. In the greater 

 whales there is reason for supposing that the ratio of the weight of 

 the brain to that of the body is ^-J^. In the smaller Cetaceans it is not 

 diminished to a proportionate size, as its extraordinary development 

 in the Dolphin testifies. 



Smell. Hunter observes that in many of the WRale Tribe there is 

 no organ of smell at all, and in those which have such an organ, it is 

 not that of a fish, therefore probably not calculated to smell water. 

 It becomes difficult therefore, he remarks, to account for the manner 

 in which such animals smell the water ; and why the others should 

 not have had such an organ, which seems to be peculiar to the large 

 and small Whalebone Whales (Balrrna myiticetus and Balcmoptcra 

 rostrata) the organ, in those which have it, he adds, is extremely 

 small, when compared with that of other animals, as well as the nerve 

 which is to receive the impression. 



Taste. The complicated and indeed delicate structure of the tongue 

 in the Phytophagous Cetaceans indicates that they must enjoy the 

 sense of taste, although the tongue is capable of but slight motion. 



But it h.is been doubted whether the Zoophagous Cetaceans are 

 endowed with a special organ for the enjoyment of this sense. No 

 fossulate nor conical papillae are present in the tongue of the Dolphin 

 or of the Porpesse ; slight elevations, the middle of which appears to 

 be perforated, are only perceptible, and the fringed edges would seem 

 to lead to the notion that their object is more intended for 

 furthering the sensations of touch. 



John Hunter states that the tongue, which is the organ of taste, is 

 also endowed with the sense of touch. He found the tongue in the 

 Porpesse and Grampus firm in texture, composed of muscle and fat, 

 pointed and serrated on its edges like that of a hog. In the Spermaceti 

 Whale, he says, it was almost like a feather-bed. In the Piked 

 Whale it was but gently raised, hardly having any lateral edges, and 

 its tip projecting but little, yet like every other tongue, composed or 

 muscle and fat. He supposes that the tongue of the large Whale- 

 bone Whale rises in the mouth considerably ; the two jaws in the 

 middle being kept at such a distance on account of the whalebone, so 

 that the space between, when the mouth is shut, must be filled with 

 the tongue. 



Sight. The eye in the Herbivorous Cetaceans only is provided 

 with a nictitating membrane, or lateral lid ; that of the Zoophagous or 

 Spouting Cetaceans has no lachrymal glands, but the lids are furnished 

 with glands for a mucous secretion adapted for lubricating the 

 sclerotic coat. 



John Hunter states that the eye in this tribe is constructed upon 

 nearly the same principle as that of the quadrupeds, differing how- 

 ever in some circumstances, by which it is probably better adapted to 

 see in the medium through which the light is to pass. It is upon 

 the whole small for the size of the animal. The lids have but little 

 motion, and consist not of loose cellular membrane, as in common 

 quadrupeds, but rather of the common adipose membrane of the body ; 

 the connection however of their circumference with the common 

 integuments is loose, the cellular membrane being less loaded with 

 oil, which allows of a slight fold being made upon the surrounding 

 parts in opening the eyelids. This is not to an equal degree, he adds, 

 in them all, being less so in the Porpesse than in the Piked Whale. 

 A detailed account of the anatomy of the eye in whales will be found 

 in Hunter's paper. 



Hearing. There is no external concha, but the ear is constructed 

 much upon the same principle as in the quadruped ; there are how- 

 ever certain difl'erences which the reader will find set forth in Hunter's 

 paper. The sense seems to be fairly developed, and whale-fishers 

 experience no small difficulty from the warning given by both eye 

 and ear. It has however been stated that the Greenland Whale, 

 though not without a nice sense of hearing, remains insensible to the 

 report of a cannon. 



Touch. The sensation of touch must be lively, though it is a 

 commonly received opinion that the common Dolphin, notwithstanding 

 its delicate epidermis, is not very sensible to tactile impressions. 

 Messrs. Breschet and Roussel de Vauzeme distinguish the following 

 constituents in the skin of the Cetaceans : 1. Derm, or coriuin, a 

 dense fibrous cellular texture, which contains and protects all the 

 other parts of the skin. 2. The papillary bodies, consisting of 

 papilhe covered by the derm. 3. The sudorific apparatus, consisting 

 of soft, elastic, spiral canals, which extend through the entire thick- 

 ness of the derm, and open in the intervals of the papilla; by an 

 orifice, closed generally by a small epidermic valve. 4. The inhalent 

 apparatus, 5. The mucous apparatus. 6. The colorific apparatus. 



