Chapter 1

The dissection of the Cetacea, and more especially of the larger kinds, is attended with great difficulty, and not unfrequently entails heavy expenses on those who attempt it. For these reasons I have thought that zoologists might be pleased to have, even now, submitted to them the results of numerous dissections made many years ago, when, not stinted in means, and having the aid of excellent assistants, I attempted the dissection even of the gigantic Arctic Rorqual, the largest, perhaps, of all living beings. Certain of the details have been from time to time laid before the public, but in an extremely scattered and incomplete form, and without the illustrations (artistic), which explain so much better than any verbal description. The greater part is still before me in manuscript. It is my intention in the following contributions to endeavour to connect them together, adding to those already published many facts I find in MSS. The original drawings, made by my brother and by Messrs. Edward Forbes and Henry Goodsir (who were at that time my students and assistants), are still in my possession.

_Determination of Species._--The determination of species as regards the _Cetacea_ is one of much difficulty; Cuvier met this difficulty by an appeal to anatomy. The number of vertebræ composing the vertebral column (exclusive of the cephalic) seemed to me a tolerably secure guide in the determination of species,--being aware, however, that some doubted the method, believing that the number of the vertebræ might vary, first, with the individual, secondly with the age of the specimen. I still continue to be of my original opinion, that the number of vertebræ comprising the vertebral column, properly so called, may safely be trusted in determining the species of the Cetacea; and with this view I drew up the following Table, excepting from it the genus _Dugong_, which I have never considered to be a Cetacean:--

_Tabular View of the Number of the Vertebræ in certain Cetacea._

(Cephalic vertebræ excluded.)

| Authorities. | | --------------------------------------------------- | SPECIES. | CUVIER. RUDOLPHI. KNOX. J. HUNTER. HUNTER | | | (Glasgow.)| --------------------------------------------------------------------- | | | | | | | |1. MYSTICETUS. | | | | | | |Skeleton of the | | | | | | |foetus (the | | | | | | |cervical reckoned| | | | | | |as 7) of the | | | | | | |_Mysticetus_ | | | | | | |_borealis_, | | | | | | |Greenland | | | 48 | | | | | | | | | | |Adult | | | | | | |_Mysticetus_, | | | | | | |Whale of | | | | | | |Commerce. | unknown | | | | | | | | | | | | |_B. Mysticetus_ | | | | | | |_australis_, True| | | | | | |Whale of the Cape| | | | | | |Seas | 59 | | | | | | | | | | | | |2. BALÆNOPTERA. | | | | | | |Gigantic Northern| | | | | | |Rorqual | | | 65 | | | | | | | | | | |Specimen of | | | | | | |Rorqual described| | | | | | |by Rudolphi | | 54 | | | | | | | | | | | |_B. rostrata_ of | | | | | | |Fabricius; on the| | | | | | |authority of Van | | | | | | |Beneden: A. | | | | | | |Rorqual | | | | | 48 | | | | | | | | |Great Whale at | | | | | | |Antwerp. Van | | | | | | |Beneden. Species | | | | | | |not stated | | | | | 61 or 62. | | | | | | | | |The lesser | | | | | | |Rorqual of the | | | | | | |North | | | 48 | 46 | 46 | | | | | | | | |Great Rorqual of | | | | | | |the Cape | 52 | | | | | | | | | | | | |3. PHYSETER. | | | | | | |Sperm Whale or | | | | | | |Cachalot | 60 | | | | | | | | | | | | |4. DELPHINUS. | | | | | | |_D. Delphis_ | 67 | | | | | | | | | | | | |_D. Delphis._ In | | | | | | |my museum | | | 81 | | | | | | | | | | |_D. Delphis._ In | | | | | | |the Museum of Dr.| | | | | | |R. Hunter, | | | | | | |Glasgow | | | | | 90 | | | | | | | | |_D. Delphis._ | | | | | | |Dissected by John| | | | | | |Hunter | | | | 60 | | | | | | | | | |_D. Phocæna_ | 66 | | 65 | 51 | | | | | | | | | |_D. Ebsenii._ Van| | | | | | |Beneden | | | | | 90 | ---------------------------------------------------------------------

In a late number of the 'Bulletins of the Royal Academy of Brussels' I find some valuable remarks in respect of these points by M. Van Beneden. He praises, and deservedly, no doubt, the exertions of M. Eschricht to collect a proper Museum of the Cetacea. It appears, according to M. Eschricht, that at no age whatever do we find in true whales (meaning, I presume, the _Mysticetus borealis_ and _australis_) any distinct vertebræ in the cervical region as in other mammals. A fusion of all into one bone or cartilage seems to take place even in the youngest foetus. In the foetus examined by me of this species (a specimen removed from the uterus of a true _Mysticetus_ killed in the Greenland seas), I do not recollect the precise appearance of the cervical vertebræ; but the skeleton is in existence, and shall be referred to. To the skeleton of the Rorqual now in the Museum at Antwerp, and which seems to me of the same species as the one I dissected in Scotland (and of which the skeleton, prepared with infinite care by my brother and myself, was presented by me to the Town Council of Edinburgh, and is now preserved in the Zoological Gardens of the same city), he gives the following vertebræ:--

Skeleton of the Rorqual at Antwerp--Cervical 7 Dorsal 14-15 Lumbar 15 Caudal 25[C] -------- Total 61 or 62

In the skeleton of the Great Rorqual now in the Zoological Gardens at Edinburgh, and originally dissected and prepared by my brother and myself, these vertebræ are--

Cervical 7 Dorsal 15 Lumbar and Caudal 43 -- Total 65

In that of the Lesser Rorqual I dissected in 1830, the skeleton of which I think is still preserved in the Museum of the University of Edinburgh, we found--

Vertebræ. Cervical 7 Dorsal 11 Lumbar 13 Caudal 17 -- Total 48

The specimen was that of a young animal, and of the same species, I believe, as the one described by Mr. Hunter and Fabricius; it is a distinct species, and not merely the young of the Great Rorqual.

I shall return to the Dugong, as not being a Cetacean, in a future Section: its skeleton has been examined in a masterly way by De Blainville, an anatomist and observer of the highest order, since the time I wrote and published my Memoir on the Dugong.

The first great step in the anatomy of the Cetacea is unquestionably due to Cuvier; but his dissections were almost confined to the genus _Delphinus_, or the common Porpoise of our coasts. I repeated all his dissections, and found them, as they almost always were, scrupulously exact; but when I came to examine Cetacea with whalebone instead of teeth, I was surprised to find how different, in fact, the anatomy of the two great families was. Scarcely in any great natural family do we find Cuvier's favourite theory of anatomical and physiological co-relations so entirely at fault as in the Cetacea. The teeth or whalebone, as natural-history characters, lead to no results; the whole structure of the interior defies all _à-priori_ reasoning. The brain in whalebone-whales does not fill the interior of the cranium; so that the capacity of the one is no measure of the solid bulk of the other. Their food is various, having no relation to the teeth or buccal appendages; vascular structures surround the spinal marrow, and extend in the _Balænopteræ_ into the cavity of the cranium, which seem to be without any analogy in other mammals, or, at the least, a very obscure one, and whose functions are wholly unknown.

Cetacea might with some propriety be divided into whales with whalebone, and whales with teeth. Those with whalebone have rudimentary teeth in both jaws in the foetal state. Fossil Cetacea exist, and they seem to have been of both kinds, but, no doubt, were generically and specifically distinct from the recent. Judging from the remains of those I have seen, I am inclined to think that those with teeth were of a stronger and firmer build in the skeleton than those called recent; that the neck was longer, and the caudal portion of the column shorter than in the recent kinds, and that they approached the Saurians in form. There is a remarkable want of symmetry in the crania of some of the Cetacea; but most remarkable is the cranium of the Narwhal. Of this fact I have already spoken, in the article published in the Transactions of the Royal Society of Edinburgh.

_Delphinus Phocæna. Dissection of a small Cetacean sent to me from Orkney in the month of May 1835._--This species is said to abound on the coasts, and to furnish a kind of fishery to the inhabitants. On dissection we found 81 vertebræ, exclusive of the cephalic. The species must be quite distinct from those previously and subsequently examined by myself and many others, in which the number of vertebræ ranged from 61 to 66. It is also, I think, distinct from the specimen I saw in Dr. R. Hunter's Museum in Glasgow, in which the number of vertebræ was 90, exclusive of the cephalic in all the cases. Thus it stands with regard to the Cetacea called Porpoises and Dolphins.

In certain species of _Delphinus_ the vertical column is composed of 61 vertebræ, in others of 65, in others of 66, in others of 81, in others of 90.

The specimen I now describe was, no doubt, that of a young animal; and the skeleton was prepared, consequently, as a natural one. This method has the advantage of security against the loss of any important osseous structures, which too frequently happens when the bones require to be macerated. The bones contained little oil, and weighed, head included, only 7-1/4 lbs.; the whole animal, when entire, weighed 14 stone, or 196 lbs.; the skeleton therefore was about a twenty-fourth part of the whole weight. It was a female. The external nostrils terminated in a single orifice of a semilunar shape, with the concavity turned towards the snout. Measurements of young animals have not the importance of those of the adult; but I give them here because I think that the specimen, although young, had nearly attained its full growth:--

ft. in. Total length over the dorsum 6 5-2/8 Total length lateral surface 6 11-2/8 Total length abdominal surface 6 11-2/8 From the snout to the nostrils 0 11-4/8 From the nostrils to the dorsal fin 1 6-4/8 Base of the dorsal fin 0 11 From dorsal fin to foot of tail 3 0-2/8 Breadth of pectoral limb 0 4-4/8 From the snout to the organs of generation 3 9-4/8 Circumference anterior to the arm 2 9 Circumference anterior to dorsal fin 3 2-4/8 Circumference posterior to dorsal fin 2 10 Circumference at setting on of the tail 0 8-4/8 Length of pectoral limb 0 10 Breadth of tail 1 2 Greatest height of the dorsal fin 0 9

From the notes taken at the time, I find that my brother remarks that the Dolphin of Orkney differed a good deal in shape from those found in the Forth and seas in the South of Scotland. There were, moreover, 16 more vertebræ than in the skeleton of the Common Porpoise of authors. The teeth generally weighed 2-1/2 grains each.

Further, the muscles of the tongue, intrinsic as well as extrinsic, were extremely well developed. The isthmus faucium was 3 inches long. All this part was extremely glandular. A well-marked muscular gullet followed, composed of two layers of muscular fibres,--one circular internally, and one longitudinal externally. These latter sent a slip to the base of the arytænoid cartilages. The mucous membrane of the gullet had no true epidermic covering, and in this respect differed remarkably from the first gastric compartment, from which a cuticular lining could be peeled off, as strong as that from the sole of the foot in man. The larynx presented that organization so well described by the illustrious Cuvier, and which I believe to be peculiar to the whales with teeth. It differs very much, as I explained long ago, in its arrangement from that of Whalebone Whales,--a fact of which I think Cuvier was not aware. The cricoid cartilage was imperfect in form; the hyo-epiglottic muscles very strong. The proper arytænoid were present, and strong, but did not extend so high as in man; the thyro-arytænoid muscles were very fully developed. In the interior of the larynx there were no projections nor ventricles, no cuneiform cartilages, nor cornicula laryngis. The rings of the trachea formed complete circles.

_Stomach._--The cuticular lining is limited to the first cavity or compartment. It is in the second compartment that is found the curious glandular arrangement first, I believe, described by me in the 'Transactions of the Royal Society of Edinburgh.' This structure is most probably not limited to the second compartment. There are four distinct compartments in the stomach of this animal. A dilated duodenum follows, 6 inches in length. It is possible that this may have been in some instances mistaken for a stomach. The valvulæ conniventes commence with the jejunum; these are longitudinal, and extend to within about 6 inches of the anus, terminating at a point where the intestine seems enlarged. The length of the intestines, large and small, was 90 feet; circumference generally about 2 inches. Thousands and tens of thousands of parasitical worms were found in the stomach, but none in the intestine. In the stomach also we found four mandibles of the cuttlefish, but no remains of anything in the intestines, and no parasites.

_Heart and Vessels._--The heart weighed exactly one pound. The Eustachian valve was small, that of Thebesius imperfect. The aorta proceeded for about 3 inches of its course before giving off any branches. At a point corresponding to the 15th or 16th lumbar vertebra the vessel divided into the common iliacs. The _art. sacri media_, its continuation, continued its course protected by the V-bones, and giving off branches corresponding to the intervertebral spaces.

_Brain and Nervous System._--The erectile tissue surrounding the spinal cord and origin of the spinal nerves in the Cetacea did not extend into the interior of the cranium. The entire encephalic mass weighed 2-1/2 lbs.: cerebrum, 2 lbs.; cerebellum, 1/4; pons and medulla, 1/4 = 2-1/2. Compared with a drawing of Camper of the _Delphinus Phocæna_, the brain was found to differ remarkably, in being much broader in the line of the middle and posterior lobes. In no animal did I ever find the fibrous structure of the brain so well marked; and this extended to the cerebellum[D]. I give here some measurements of the brain, which may be of use to future observers. The brain is short from before backwards, but broad transversely:--

Antero-posterior diameter 5-2/8 inches. Breadth 8 inches. Greatest breadth of the cerebellum 4 inches. Length of the cerebellar hemisphere 4-6/8 inches. Depth of ditto 3-2/8 inches. Weight of the encephalic mass 2-1/2 lbs. Depth of the interhemispherical fissure 1-2/8 inches. Length of the corpus callosum 1-7/8 inches. Weight of cerebrum 2 } Weight of cerebellum 0-1/4} = 2-1/2 lbs. Weight of the pons and med. oblongata 0-1/4}

_Nerves._--The 7th pair was found to be unexpectedly large and firm, including both portions. The anterior roots of the spinal nerves were far more numerous than the posterior or dorsal.

_Muscles._--The panniculus carnosus, strong and fleshy, extended nearly over the whole trunk. The recti abdominis were powerful, and attached inferiorly in this way:--A portion runs to the pelvic bones; a much stronger to a strong aponeurosis, situated between the anus and the root of the tail.

The erector muscles of the spine (sacrolumbalis, longissimus dorsi and multifidus spinæ) weighed fully 16 lbs. They had but slender costal attachments; but their spinal (small delicate tendons) were innumerable. The scaleni were very large; and the vessels held the same relation to them as in man. The serratus magnus was comparatively small. The larger rhomboid had no spinal attachment; the minor rhomboid seemed to be the larger of the two. The pectorals were comparatively small. The adipose tissue appeared to be wholly confined to the subcutaneous region. The muscles were of a deep brown colour, full of blood, with a short, dark, and well-flavoured fibre: when cooked, they had a strong resemblance in flavour and taste to the flesh of the hare.