272 DE. J. MTTRIE ON THE OEGANIZATION OF THE CAAING WHALE. 



VII. The Nervous Centre. 



I can only offer a disjointed fragment concerning the brain, which in the present 

 instance was scooped out piecemeal through the foramen magnum. The portions thus 

 rudely extracted comprised almost, if not quite, the entire encephalon ; but this was 

 softened and decomposed. It weighed altogether 5^ lbs. avoirdupois. If the body 

 weighed a ton, or thereabouts, as estimated by the railway officials during transport 

 of the creature, then the brain would approximately be something like 4^ of the 

 weight of the body. 



Portions of the cerebrum, somewhat more intact than others, showed that, as in the 

 Porpoise, the brain of the Pilot Whale is highly convoluted, and that likewise there is 

 a very considerable superficial thickness and amount of grey matter covering the white 

 substance. The tentorium is composed of a strong fibrous texture. 



An accurate and detailed account of the brain of a large Cetacean is a great deside- 

 ratum, but one which as yet is not easy to be provided. I look forward, therefore, with 

 interest to Professor Turner's promised contribution in this untrodden field. 



VIII. Fleshy Motor Agents op Body and Limbs. 



When I made my dissection, and had the accompanying plates lithographed, illustra- 

 tions of the kind (/. e. showing the whole body and in layers) were unknown to me. 

 Indeed, in this respect I believe they will still stand ground as original views. The 

 literature on Cetacean myology has since received considerable accessions, especially as 

 regards limb-fiexors and extensors. Several authorities thereon have already been 

 quoted in my preliminary note, antea, p. 235. 



1. Muscles acting chiefly on the Pectoral Limb. — The superficial layer, that which 

 represents the panniculus carnosus of land Mammals, is distributed over nearly the 

 whole surface of the body, but leaves the tail free. What corresponds to Cuvier's 

 thoracico-fascien, or may be equivalent to platysma myoides, covers the throat from the 

 angle of the mouth back to the pectoralis major. According to the part of the body 

 so are the fibres of the entire panniculus differently directed ; and they taper posteriorly 

 upon the side vertically above the genital outlet. A great expanse seems to act upon 

 the pectoral extremity, both superficially and deeply through an axillary portion 

 (Cuvier's dermo-humerien) joining the latissimus dorsi. A semirotating motion, there- 

 fore, is imparted to the limbs. The great expanse of tliis muscle and the accessory 

 offshoot to the fore limb present little deviation among the Whale tribe. 



the description runs : — " A portion of a plexus of absorbent vessels from the head of a Spermaceti- Whale 

 (Physeter macroce/pJmlus, Linn.), filled with spermaceti, which was by their action in process of removal. This 

 most valuable preparation affords a strong argument in favour of the doctrine that the waste and superfluous 

 parts are removed by the absorbents, and not by the veins." On the contrary, consult Professor Wharton 

 Jones's " Caudal Lymphatic of the Eel," Phil. Trans. 1868, p. 675 ; where he demonstrates the phenomena 

 attending the propulsion of the lymph from the caudal heart into the caudal vein &c. 



