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THE POPULAR SCIENCE MONTHLY. 



bristly fibers, so that the roof of the whale's mouth looks as if covered 

 with hair, as described by Aristotle. The blades are longer near the 

 middle of the series, and gradually diminish near the front and back 

 of the mouth. The horny plates grow from a dense, fibrous, and highly 

 vascular matrix, which covers the palatal surface of the maxillae, and 

 which sends out lamellar processes, one of which penetrates the base of 

 each blade. Moreover, the free edge of these processes is covered with 

 very long, vascular, thread-like papillae, one of which forms the central 

 axis of each of the hair-like epidermic fibers of which the blade is 

 mainly composed. The blades are supported and bound together, for a 

 certain distance from their base, by a mass of less hardened epithelium, 

 secreted by the surface of the palatal membrane or matrix of the whale- 

 bone in the intervals of the lamellar processes. This is the " interme- 

 diate substance " of Hunter, the " gum " of the whalers. 



The function of the whalebone is to strain 

 the water from the small marine mollusks, crus- 

 taceans, or fish upon which the whales subsist. 

 In feeding they fill the immense mouth with 

 water containing shoals of these small creatures, 

 and then, on their closing the jaws and raising 



Fig. 4. Whalebone Whale, or Greenland Whale. 



the tongue, so as to diminish the cavity of the mouth, the water streams 

 out through the narrow intervals between the hairy fringe of the whale- 

 bone blades, and escapes through the lips, leaving the living prey to 

 be swallowed. Almost all the other structures to which I am specially 

 directing your attention are in a more or less rudimentary state in 

 the Cetacea ; the baleen, on the other hand, is an example of an ex- 

 actly contrary condition, but an equally instructive one, as illustrating 

 the mode in which Nature works in producing the infinite variety we 



