196 



CETACEA. MAMMALIA.- 



stomach, neither is there any inter-communicating 

 channel common to the three first cavities, by which 

 the aforesaid function could be maintained. In the 

 accompanying figure A represents the oesophagus, B, C, 

 D, and E the four stomachal compartments, P the 

 duodenum. The only approach to any unusual exten- 

 sion of the internal secreting membrane, is such as 

 is gained by the presence of numerous rugae or foldings, 

 which are more or less irregularly disposed throughout 

 the entire compartments. Of the other circumstances 

 in connection with the alimentary canal which call for 

 particular attention, are those which refer to the great 

 length of the intestinal tube, and to the presence or 

 absence of a ccecum. Most of the spouting whales 



Fig 78. 



Compound stomach of the White Whale (Beluga Catodon). 



have no coecum, but this appendage is present in 

 the mysticete and in the piked whale. The chylo- 

 poietic viscera exhibit several peculiarities of form 

 which need uot be dwelt upon ; but we may remark, 

 in passing, the entire absence of any gall-bladder 

 in the zoophagous species, whilst it is present in 

 the herbivorous forms. The reproductive organs are 

 largely developed, the mammae of the female being 

 placed in the inguinal region in the true whales and 

 dolphins, and in the pectoral region in the phytopha- 

 gous manatees and dugongs. The circulatory system 

 has already, in part, engaged our attention, but the 

 contemplation of such a marvellous machinery in these 

 bulky creatures deserves some further comment. The 

 amount of muscular pressure required to propel the life 

 stream from the voluminous cavities of the heart of a 

 rorqual is something well calculated to excite the 

 astonishment of any one possessing the slightest ac- 

 quaintance with the principles of hydraulic power. 

 The main arterial trunk of the spermaceti whale has a 

 circumferential measurement of at least three feet, "and 

 when," says the illustrious John Hunter, " we consider 

 these as applied to the circulation, and figure to our- 

 selves that probably ten or fifteen gallons of blood are 



thrown out at one stroke, and move with an immense 

 velocity through a tube of a foot diameter, the whole 

 idea fills the mind with wonder." Generally speaking, 

 the form of the heart is precisely similar to that of 

 other mammals, but in the phytophagous dugong the 

 apex of the heart is deeply cleft, so that the ventricles 

 are partly detached from one another. In regard to 

 the venous system, it should also be noted that its 

 arrangements, in some parts, are even more plexiform 

 than obtains in the arteries. This is particularly seen 

 in the branches of the great anterior vena cava, and 

 more especially in the veins which surround the spinal 

 cord; whilst another still more interesting peculiarity 

 connected with this system, is, that scarcely any of the 

 veins are furnished with valves internally. 

 All these conditions are admirably adapted to 

 the suboceanic habits of the cetaceans, and 

 taken in connection with other structures yet to 

 be described, manifestly indicate evidences ot 

 harmonious design. We allude here principally 

 to the character of the dermal and subcutaneous 

 investment of the body. This consists essen- 

 tially of the same elements which enter into the 

 composition of the hide of ordinary quadrupeds ; 

 but nearly all trace of hares or bristles have 

 disappeared in the zoophagous species, these 

 structures being represented only in the embry- 

 onic condition of dolphins and in adult whales, 

 by a few bristles attached to the anterior part 

 of the upper or lower jaws. In some species 

 the cuticle is rather thin, but in others it 

 attains a remarkable development, and we have 

 observed it to be upwards of an inch in thick- 

 ness in the great rorqual. In like manner the 

 corium acquires remarkable density and strength, 

 passing gradually into a fatty tissue, which is 

 commonly called the blubber, and which varies 

 in quantity in different species, being in some 

 found only a few inches thick, and in others 

 surrounding the muscles to the depth of a foot and 

 a half or even two feet below the cuticular surface. 

 The larger kinds of whale are capable of yielding 

 upwards of twenty tons of oil, and as the oil is 

 worth about 30 per ton, the "whale fishery," as 

 it is erroneously termed, proves a very lucrative 

 trade. Upwards of twenty thousand tons are annually 

 brought to this country by British whalers, notwith- 

 standing the Americans and other nations have vastly 

 increased the competition of late years. "In 1821," 

 says the late Professor Edward Forbes, " the British 

 whale fishery employed one hundred and fifty-nine 

 ships, but the decline of the northern fisheries has 

 reduced their number to the half. We are compen- 

 sated for this, however, in the energy and success with 

 which our Australian colonies are joining in the busi- 

 ness; and the rich source of blubbery wealth which 

 the north once was, the south now promises to be. At 

 present we are beaten in whaling by our American 

 cousins; but the great advantages presented by the 

 proximity of Australia and the Auckland Isles to the 

 southern whaling grounds, are giving us a fresh start, of 

 which we will not be slow to avail ourselves. In 1844 

 the American whaling fleet numbered no fewer than 



