GIANTS OF THE DEEP 309 



A creature possessed of such enormous bulk must of necessity 

 live in the water, and, moreover, in the sea. But, it may be asked, 

 why should this be so ? The answer is, that most mammals which 

 are found on land have the body supported by two pairs of limbs, 

 and this body may well be compared to a bridge supported by 

 pillars. If the pillars of a land bridge are not constructed in such. 

 a way that the main portion is well supported, and its arches built 

 strong and rigid, a sudden collapse is assuredly threatened ; but if 

 the bridge is laid on the water (i. e. a boat-bridge), it is not necessary 

 that the structure should be of such great strength and solidity, 

 "since it is supported on the water at all points." Thus the strength 

 of the larger land animals and the immense size of the Whale will 

 be understood from this apt comparison, for, as has already been 

 noted, the Whale exceeds in size any terrestrial animal. We not 

 only find this divergence of size and firmness in the animal world — 

 that is, as between land and aquatic beasts — but even among plants 

 interesting analogies are forthcoming with regard to the size and 

 strength of water plants as compared with their neighbours, which 

 anchor themselves on land, and often have to take advantage of the 

 surrounding vegetable life, being too weak and fragile to success- 

 fully fight the great battle of existence without resorting to climbing, 

 straggling, twining, creeping, or throttling. 



The Whale is a superb diver, and in the mazy depths of the 

 ocean is as much at home as the Squirrel gambolling in the pliant 

 tree-tops or the Rabbit secure inside its burrow. But how, it may 

 be asked, is it possible for an animal of such gigantic proportions to 

 successfully overcome the enormous pressure of water consequent 

 upon the Whale's habit of passing the greater part of its existence 

 far beneath the surface of the sea? At first sight the conundrum 

 seems impossible of solution, but close acquaintance leads us to an 

 awakening. For example, "most of the bones of the body remain 

 cartilaginous 1 at their points of union, the two halves of the 

 mandible 2 are only united by ligaments, 3 and only the first pair of 

 ribs is directly united with the sternum ; 4 all these arrangements 

 tend to prevent fracture of the bones, and impart great elasticity 

 to the body." 



We have already seen during some of our previous expeditions 



1 Gristly, the bones containing little or no calcareous or limy matter. 



2 The lower jaw. 3 Short bands of strong white glistening fibres, by which 

 the bones are bound together, 4 The breast bone, 



