( ETAOKA. 



D;T 



According t.. Hunter, tin- r.-ticiilar network containing the blubber, 

 which i described by him as (in.- in the Porpesse, Spermaceti, Hud 

 large \\ halobou* Whale (Halmm), and coarae in the Onunpiw and 

 anwll Whalebone Whale (Balmoptrra), form* part of the skin. 



In giving some illiutraticnui of this large family we ahall follow the 

 arrangement of Dr. J. E. Gray an indicated above. 



The following is a synopsis of the character of the genera of the 

 first family Hal,rU<r : 



a. Dorsal fin none. Belly smooth. Baleen elongate, slender. 



b. Dorsal fin distinct. Belly plaited. Baleen broad, short 

 1 Mtyapttra. Pectoral fins elongate. Dorsal fin low. 

 3. Baimojilrra. Pectoral fins moderate. Dorsal fin falcate, 

 j length from nose. Vertebra) 54 or 64. 



It in in the genus Ralirnn that the baleen, or whalebone, is most 

 highly developed. John Hunter describes this extremely elastic 

 niml substance as being of the same nature as horn, a term which 

 he uses to express what constitutes hair, nails, claws, feathers, &c. 

 It consists, he remarks, of thin plates of some breadth and in some of 

 very considerable length, their breadth and length in some degree 

 corresponding to one another ; when longest they are commonly the 

 broadest, but not always so. The plates differ in size in different 

 parts of the same mouth, more especially in the large Whalebone 

 Whale. "They are placed," continues Hunter, "in several rows, 

 encompassing the outer skirts of the upper jaw, similar to teeth in 

 other animals They stand parallel to each other, having one edge 

 towards the circumference of the mouth, the other towards the centre 

 or cavity. They are placed near together in the Piked Whale, not 

 being a quarter of an inch asunder, where at the greatest distance, yet 

 differing in this respect in different parts of the same mouth ; but in 

 the Great Whale the distances are more considerable. The outer row 

 is composed of the longest plates ; and these are in proportion to the 

 different distances between the two jaws, some being 14 or 15 feet 

 long and 12 or 15 inches broad ; but towards the anterior and posterior 

 parts of the mouth they are very short, they rise for half a foot or 

 more, nearly of equal breadths, and afterwards shelve off from their 

 inner side until they come near to a point at the outer : the exterior 

 of the inner rows are the longest, corresponding to the termination of 

 the declivity of the outer, and become shorter and shorter till they 

 hardly rise above the gum. The inner rows are closer than the outer, 

 and rue almost perpendicularly from the gum, being longitudinally 

 straight, and have less of the declivity than the outer. The plates 

 of the outer row laterally are not quite flat, but make n serpentiiu- 

 line ; more especially in the Piked Whale the outer edge is thicker 

 than the inner. All round the line made by their outer edges runx a 

 small white bead, which is formed along with the whalebone, and 

 wean down with it The smaller plates are nearly of on equal thick- 

 ness upon both edges. In all of them the termination is in a kind of 

 hair, as if the plate was split into innumerable small parts, the exterior 

 being the longest and strongest The two sides of the mouth com- 

 posed of these rows meet nearly in a point at the tip of the jaw, and 

 spread or recede laterally from each other as they pass back ; and at 

 their posterior ends in the Piked Whale they moke a sweep inwards, 

 and come very near each other, just before the opening of the oeso- 

 phagus. In the Piked Whale there were above 300 in the outer rows 

 on each side of the mouth. Each layer terminates in an oblique 

 surface, which obliquity inclines to the roof of the mouth, answering 

 to the gradual diminution of their length ; so that the whole surface, 

 composed of these terminations, forms one plane, rising gradually 

 from the roof of the mouth : from this obliquity of the edge of the 

 outer row we may in some measure judge of the extent of the whole 

 base, but not exactly, as it makes a hollow curve, which increases the 

 base. The whole surface resembles the skin of an animal covered 

 with strong hair, under which surface the tongue must immediately 

 lie when the mouth is shut ; it is of a light-brown colour in the Piked 

 Whale, and is darker in the Large Whale. In the Piked Whale, when 

 the mouth is shut, the projecting whalebone remains entirely on the 

 inside of the lower jaw, the two jaws meeting everywhere along then- 

 surface ; but how this is effected in the Large Whale I do not certainly 

 know, the horizontal plane made by the lower jaw being straight, as 

 in the Piked Whale ; but the upper jaw being an arch cannot be hid 

 by the lower. I suppose therefore that a broad upper lip, meeting as 

 low as the lower jaw, covers the whole of the outer edges of the 

 exterior rows. The whalebone is continually wearing down, and renew- 

 ing in the same proportion, except that when the animal is growing 

 it is renewed faster and in proportion to the growth. The formation 

 of the whalebone is extremely curious, lieing in one respect similar to 

 that of hair, boms, spurs, Ac. ; but it has besides another mode of 

 growth and decay equally singular. These plates form upon a vascular 

 substance, not immediately adhering to the lower jaw-bone, but 

 having a more dense substance between, which is also vascular. 

 This substance, which may be called the nidus of the whalebone, 

 sends out (the above) thin broad processes, answering to each plate, 

 on which the plate is formed, as the cook's spur or the bull's 

 horn, on the bony core, or a tooth on its pulp; so that each 

 plate is necessarily hollow at its growing end, the first part of the 

 growth taking place on the inside of this hollow. Besides this 



mode of growth, which is common to all such substances, it 

 receives additional layers on the outside, which arc formed from 

 the above-mentioned vascular substance extended along the surface 

 of the jaw. This part also forms upon it a m-mi-horny substance 

 between each plate, which is very white, rises with the whalebone, 

 and becomes even with the outer edge of the jaw, and the termi- 

 nation of- its outer part forms the bead above i> This 

 intermediate substance fills up the spaces between the plates as 

 high as the jaws, act* as abutments to the whalebone, or is similar to 

 the alveolar processes of the teeth, keeping them firm in their places. 

 As both the whalebone and the intermediate substance are constantly 

 growing, and as we must suppose a determined length necessary, a 

 regular mode of decay must be established, not depending entirely on 

 chance, or the use it is put to. In its growth three ports appear to 

 be formed : one from the rising core, which is the centre ; a second 

 on the outside ; and a third being the intermediate substance. These 

 appear to have three stages of duration ; for that which forms on the 

 core, I beljeve, makes the hair, and that on the outside makes princi- 

 pally the plate of whalebone. This, when got a certain length, breaks 

 off, leaving the hair projecting, becoming at the termination very 

 brittle ; and the third or intermediate substance, by the time it rises 

 as high as the edge of the skin of the jaw, decays and softens away 

 like the old cuticle of the sole of the foot when steeped in water. 

 The use of whalebone, I should believe, is principally for the retention 

 of the food till swallowed; and I suppose the fish they catch .uv 

 small when compared with the size of the mouth." (Hunter ' On 

 Whales.') 



View of the inside of the jaw of a foetal Baltranplrra, showing the nrron(femeo>. 

 of the Whalebone. (Owen, ' Odontograpby.') 



The following notes by Dr. J. E. Gray contain the result, "f the most 

 recent observations on this curious production iu the < 'rlacea : 



" The baleen, or whalebone, has generally been considered as the 

 teeth of the whale ; but this must be a mistake, for Mr. Knox 

 observes : ' In the foetal B. myitirrtiw 60 to 70 dental pulps were 

 found on each side of each jaw, making the whole number amount to 

 from 260 to 300. The preparation (No. 56) exhibits a portion of tin- 

 gum with 12 pulps. Had these pulps been confined to the upper jaw, 

 and corresponded to the number of baleen plates, it would him -tWinnl 

 a strong analogy between the baleen and teeth ; but the number of 

 baleen plates in the whale greatly exceeds the number of dental 

 pulps; and the lower jaw, which contained an equal numlx-r of puljw 

 with the upper, has neither teeth nor baleen in the adult whale. 

 Their presence therefore in the I </* forms one of tin- 



most beautiful illustrations of the unity of organisation in the aniin.-il 

 economy. The teeth iu the Baifrna never cut the gum, but become 

 gradually re-absorbed into the system ; the very cavity in which the 

 gums were lodged disappears ; whilst, to suit the purposes of nature, 

 the integiiin MI furnishes the baleen. \\ 1 



modified form of hair and cuticle.' (Knox, ' Cat Whales,' 22.) Pro- 

 fessor Eschricht has shown also that the frotus of .17. <//.'"" liuopt 

 (' Danish Trans.,' xi. t 4, 1846) has nunicr.pus t.-.-tl. <m the edge of the 

 jaw, though they an- never developed. I am inclined to ivpu-.l the 

 baleen as a peculiar development of h.iir in the palates of these 

 animals, and somewhat analogous to the hair found in the palates of 

 the genus Leptu. 



"From the examination I have been able to make of the baleen of 

 Balccnoptcra roitrala, and of different masses of small blades of JMataa 

 amtralit, it would appear as if there was, at least in these two species, 

 two series of baleen on each side of the palate ; the external series 

 being formed of large triangular blades placed at a certain distance 



