1883.] on WJtales, Past and Present, and their Prohahle Origin. 369 



still further outward sweep before thej meet at the symphysis in 

 front, giving the floor of the mouth the shape of an immense spoon. 

 The baleen blades attain the number of 350 or more on each side, 

 and those in the middle of the series have a length of ten or even 

 twelve feet. They are black in colour, fine and highly elastic in 

 texture, and fray out at the inner edge and ends into long, delicate, 

 soft, almost silkv, but very tough hairs. 



How these immensely long blades depending vertically from the 

 palate were packed into a mouth the height of which was scarcely 

 more than half their length, was a mystery not solved until a few 

 years ago. Captain David Gray, of Peterhead, at my request, first gave 

 us a clear idea of the arrangement of the baleen in the Greenland 

 whale, and showed that the purpose of its wonderful elasticity was 

 not primarily at least the benefit of the corset and umbrella makers, 

 but that it was essential for the correct performance of its functions. 

 It may here be mentioned that the modification of the mouth structure 

 of the Eight Whale is entirely in relation to the nature of its food. It is 

 by this apparatus that it is enabled to avail itself of the minute but 

 highly nutritious crustaceans and pteropods which swarm in immense 

 shoals in the seas it frequents. The large mouth enables it to take 

 in at one time a suflicient quantity of water filled with these small 

 organisms, and the length and delicate structure of the baleen provides 

 an efficient strainer or hair sieve by which the water can be drained 

 off. If the baleen were, as in the Eorquals, short and rigid, and only 

 of the length of the aperture between the upper and lower jaws when 

 the mouth was shut, when the jaws were separated a space would be 

 left beneath it through which the water and the minute particles of 

 food would escape together. But instead of this, the long, slender, 

 brush-like ends of the whalebone blades, when the mouth is closed, 

 fold back, the front ones passing below the hinder ones in a channel 

 lying between the tongue and the bone of the lower jaw. When the 

 mouth is opened their elasticity causes them to straighten out like a 

 bow that is unbent, so that at whatever distance the jaws are separated, 

 the strainer remains in perfect action, filling the whole of the interval. 

 The mechanical perfection of the arrangement is completed by the 

 great development of the lower lip, which rises stifily above the jaw- 

 bone, and prevents the long, slender, flexible ends of the baleen being 

 carried outwards by the rush of vrater from the mouth, when its 

 cavity is being diminished by the closure of the jaws and raising of 

 the tongue. The interest and admiration excited by the contempla- 

 tion of such a beautifully adjusted piece of mechanism is certainly 

 heightened by the knowledge that it has been brought about by the 

 gradual adaptation and perfection of structures common to the whole 

 class of animals to which the whale belongs. 



Few points of the structui-e of whales offer so great a departure 

 from the ordinary mammalian type as the limbs. The fore-limbs are 

 reduced to the condition of simple paddles or oars, variously shaped, 

 but always flattened and more or less oval in outline. They are 



2 B 2 



