218 WHALES, PAST AND PRESENT xv 



in form, with the base attached to the palate, and the apex 

 hanging downwards. The outer edge of the blade is hard 

 and smooth, but the inner edge and apex fray out into long, 

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

 covered with hair, as described by Aristotle. The blades are 

 longest near the middle of the series, and gradually diminish 

 towards 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 each 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 fibres of which the blade is mainly composed. 

 A transverse section of fresh whalebone shows that it is 

 made up of numbers of these soft vascular papillae, circular 

 in outline, each surrounded by concentrically arranged epi- 

 dermic cells, the whole bound together by other epidermic 

 cells, which constitute the smooth cortical (so-called " enamel ") 

 surface of the blade, and which, disintegrating at the free edge, 

 allows the individual fibres to become loose and to assume the 

 hair-like appearance spoken of before. These fibres differ from 

 hairs in not being formed in depressed follicles in the enderon, 

 but rather resemble those of which the horn of the rhinoceros 

 is 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 whalebone in the intervals of the 

 lamellar processes. This is the " intermediate substance " of 

 Hunter, the " gum " of the whalers. 



The function of the whalebone is to strain the water from 

 the small marine molluscs, crustaceans, 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 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 whalebone 

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

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



