M A M M 



>rgans, are more advantageous in their backward and 

 literal situation. In consequence of the shortness of 

 he neck, and the great production of the bones in 

 idvance of the skull, the fore part of the whale is a 

 arge mass which has little or no flexure in any 

 lin'rtion ; and thus it gives a firmer point of insertion 

 o the movable portion of the spine than we meet 

 vith in any land animal, not excepting even the 

 houlder joint of the strongest winged hawk or the 

 nost powerfid eagle. 



This flexible portion of the entire length is a cone, 

 apering finely off, and gradually less heavy in its 

 >ories, and more free in its joints, as it approaches 

 he extremity ; and at that, extremity there is the ex- 

 lansion of the tail, of which the following is a sketch. 



ALIA. 



137 



It will be seen from this figure that the tail consists 

 if two lobes, the posterior edges of which are curved 

 I'ith a double flexure. This instrument does not 

 :onsist of a series of bones, like the terminations of 

 ommon mammalia, neither is it extended upon rays, 

 ike the tail fin in fishes. It is in fact not a fin, 

 hough it is usually so called ; but it answers the 

 mrpose of one, and answers it with wonderful effect, 

 ts external covering is scarcely different from that 

 if the rest of the body ; but internally it is composed 

 f tendons, exceedingly numerous, remarkable for 

 heir strength, and capable of very varied as well as 

 nost powerful motion. These tendons consist of 

 hree layers, two of which, external on each surface, 

 Dllow the direction of the lobes, and the internal one 

 rosses them obliquely. These tendons are connected 

 t'ith a great number of muscles inserted on the pro- 

 icsses of the spine, and they pass through a great 

 lumber of pulleys of ligament, so that, though the 

 ;eneral motion of the tail as a whole is striking 

 ipward or downward against, the water, the number 

 if oblique motions and changes of flexure of the lobes 

 s countless. As with the exception of the muscles 

 onnected with the swimming paws, which are com- 

 laratively few and weak, the whole motive energy is 

 onccntrated upon this organ, it is equally ready and 

 lowcrt'ul ; and perhaps, considering it as capable of 

 ;iving a blow, it is the most efficient organ in the 

 vhole animal kingdom. The texture of the portion 

 if it which takes effect is also such that it can hardly 

 ie injured. It is so tough that it cannot be torn, 

 nd so free from feeling that a stroke of it against a 

 lard substance gives no pain to the animal. If it 

 trikes a boat across the middle with the edge, the boat 

 s cut asunder as clean and as speedily as if by one 

 troke of a giant axe ; whereas if it strikes with the 

 lat of the lobes, the boat is driven to the depth of 

 nany fathoms with the swiftness of an arrow. Those 

 vho attack the whale in its strongholds among the 

 >olar ice are aware of the fatal effects of those blows, 

 ind therefore they are studious to avoid them. 



In swimming, we need not add that this instrument 

 must be most efficient. It is placed at that part of 

 the animal where a paddle or oar has the greatest 

 effect ; it has, as we have said, a steady point of in- 

 sertion, and the vertebral column which supports it 

 tapers at that rate which combines the rnuximum of 

 strength and elasticity ; and therefore, without the 

 assistance of fin or scale, or the deriving any assist- 

 ance from contrary flexures of the body, it dashes 

 the animal onward at an exceedingly rapid rate. 



The absolute rate of tjie whale's motion is of course 

 not known, and cannot be known, as a mathematical 

 quantity deduced from actual experiment, in which 

 both time and distance are known ; but some theo- 

 retical estimates which have been made, founded on 

 the form of its body, and the force with which its 

 swimming lobes strike the water, lead to the conclu- 

 sion that the rate of its progress exceeds twenty-two 

 miles in the hour ; and this is not unlikely, because 

 many birds which have to bear up their weight in the 

 air are capable of moving at a far more rapid rate 

 than this, and continuing their motion for many hun- 

 dreds of miles. On this subject, however, it is im- 

 possible to speak with precision, but we may well 

 suppose that in animals so finely constructed for pro- 

 gressive motion, and nearly of the same weight as 

 the medium in which they move, the rate of motion 

 may be even more rapid than this. Such powers 

 give these animals full command of the most exten- 

 sive oceans ; and as, when the polar seas are frozen 

 in the northern hemisphere, we do not find the whale 

 migrating to the temperate seas of the same, as is 

 the case with those birds which are frozen out of their 

 polar quarters, it may be possible that these whales 

 range from the one polar sea to the other. It is true 

 that they are not found in the middle latitudes, 

 apparently resident for a season, as the spermaceti 

 whales are ; but there is not a great deal of stress to 

 be laid upon this, inasmuch as the spermaceti whales, 

 being furnished with teeth and having wide throats, 

 can find food in any sea where fish abound (and 

 surface ones abound most in middle latitudes) ; 

 whereas the Greenland whale, dependent on the 

 small animals which it can catch in its whalebone 

 net, can subsist only where such animals abound, and 

 it should seem that those fitted for the food of the 

 whale are most abundant in the high latitudes and 

 during the summer season. 



Besides their effect in turning round the body on 

 its longitudinal axis, the swimming paws of the whale 

 perform other functions. Their proper motion is 

 a cross or clasping motion, so that one whale can 

 embrace another by means of them ; and the mother 

 whale can carry her young in her arms, until it ac- 

 quires sufficient size and strength for swimming by 

 her side. 



There is another use to which the animal is enabled 

 to turn these swimming paws. When extended they 

 form a line of considerable length at right angles to 

 the axis of the body, something in the same manner 

 as the trunnions form a line at right angles to the 

 line of metal in a gun; and the whale can move the 

 axis of its body in the vertical plane upon them, much 

 in the same manner as the gun is moved upon its 

 trunnions. By this means, the whale can descend to 

 a depth and rise to the surface to breathe in much 

 less time, and with much less range in horizontal dis- 

 tance, than if its motion were regulated by the tail 

 only. The length of time that the whale can remain 

 under the water before it rises to breathe is under- 



