BALENIDE 235 
the palate, with a bare interval along the middle line. These plates 
are placed transversely to the long axis of the palate, with very short 
intervals between them. Lach plate or blade is somewhat triangular 
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. At the inner edge of each principal blade are two 
or three much smaller or subsidiary blades. The principal 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, covering the 
- palatal surface of the maxille, and sending 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 papille, 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 papill, circular in outline, each. 
surrounded by concentrically arranged epidermic cells, and the 
whole bound together by other epidermic cells, that constitute the 
smooth cortical (so-called “ enamel”) surface of. the blade, which, 
disintegrating at the free edge, allows the individual fibres to 
become loose and assume the hair-like appearance before spoken of. 
These fibres differ from hairs in not being formed in depressed 
follicles in the enderon, but rather resemble the fibres composing the 
horn of the Rhinoceros. The whalebone in fact consists of nothing 
more than modified papille of the buccal mucous membrane, with 
an excessive and cornified epithelial development. 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. Baleen varies much in colour 
in different species. In some it is almost jet black, in others slate- 
colour, horn-colour, yellow, or even creamy-white. In some the 
blades are variegated with longitudinal strips of different hues. 
Baleen differs also greatly in other respects, being short, thick, 
coarse, and stiff in some, and greatly elongated and highly elastic 
in those species in which it has attained its fullest development. 
Its function is to strain the water from the small marine molluscs, 
crustaceans, or fish upon which the Whales subsist. In feeding the 
immense mouth is filled with water containing shoals of these small 
creatures, and then, on the Whale 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 
