DE. J. MUEIE ON THE OEaANIZATION OF THE OAAINa WHALE. 249 



adjunct to the creature's correct equilibrium; for we find several widely different 

 genera of the Cetacean order wanting this appendage. It is within the range of 

 possibility it may be one of those organs the homologue of which we detect in forms 

 removed ; and to our appreciation of things, functionless, inasmuch as use to a direct 

 purpose is indiscernible. We can, notwithstanding, descry in it, both structurally and 

 positionally, a counterpart to the remarkable dorsal humps in some Bovidse and 

 Camelidae, e. g. the Zebu and Dromedary, and thus recognize another of those links, 

 besides compound stomachs &c., which entitle us to refer the Cetacea and Ruminantia 

 to some ancient primordial intervening form. 



The dimensions and shape of the dorsal fin have already been mentioned. Here it 

 needs only be noted that, from being thin and laterally compressed above, it gradually 

 thickens basally and slopes outwards, merging with the general curvatm-e of the back. 

 But this remark, it must be borne in mind, applies only to the fixed anterior moiety ; 

 for the posterior region, partly attached and partly, so to say, free, or where it becomes 

 falcate in outline, alters, and is thicker above than below. (Consult the sections in 

 PI. XXXII. figs. 17 to 24 inclusive.) 



The very distinctive character which the Deductor, like the Sperm- Whale, possesses in 

 its prominent blunt muzzle or nasal protuberance, is chiefly caused by a vast deposit of 

 a fatty, semioleaginous material. This is overlain exteriorly by the thin dermis, and 

 beneath that by thick and dense fibrous tissue. The latter decreases inwards, from the 

 fibres being wide-meshed and their permitting a sort of gristly-looking fat to be inter- 

 spersed between them. Proceeding still deeper, the denseness of the fat diminishes 

 gradually until it is succeeded by very soft blubber ; and this, again becoming slightly 

 firmer, commingles with the muscular fibres of the so-called premaxillary muscle. The 

 main direction of the interwoven fibres among the blubber is transverse, so that when 

 cut in that direction they appear as layered wavy lines of white glistening fibre, varying 

 much in thickness. 



The entire mass of the fat and blubber of the massive boss of the frontal region, 

 looked at from above, has a somewhat blunt wedge- or even heart-shaped aspect, in this 

 respect agreeing with the contour of the maxillo-premaxillary region. The apex, or 

 tapering front of the blubber, is so interwoven with the strong fibrous tissue anteriorly, 

 that near the tip of the beak (premaxUlaries) it becomes lost or indistinguishable among 

 the fibrillse. It is arched from side to side above, and also somewhat convex antero- 

 posteriorly. Inferiorly, as noted, it loses itself among the fibres of the premaxillary 

 muscles ; but as the right and left one of these have a deep sulcus between them, this is 

 filled up by a median keel-like portion of the blubber, which latter has thus below a 

 wide V-shape. The greatest length of this deposit of blubber and fat is about eleven 

 inches, the greatest vertical depth six and a half inches. 



4. Auditory Ajipendages. — No external auditory orifice was detected by me before 

 removal of the skin. On this being cut off and the subjacent fatty tissue searched, a 



