Journal of the Proceedings of the Linnean Society Vol. 3
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Various >> Journal of the Proceedings of the Linnean Society Vol. 3
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We believe we have now shown that there is a tendency in nature to the
continued progression of certain classes of _varieties_ further and
further from the original type--a progression to which there appears no
reason to assign any definite limits--and that the same principle which
produces this result in a state of nature will also explain why domestic
varieties have a tendency to revert to the original type. This
progression, by minute steps, in various directions, but always checked
and balanced by the necessary conditions, subject to which alone
existence can be preserved, may, it is believed, be followed out so as
to agree with all the phenomena presented by organized beings, their
extinction and succession in past ages, and all the extraordinary
modifications of form, instinct, and habits which they exhibit.
Ternate, February, 1858.
FOOTNOTES:
[A] This MS. work was never intended for publication, and therefore was
not written with care.--C. D. 1858.
[B] I can see no more difficulty in this, than in the planter improving
his varieties of the cotton plant.--C. D. 1858.
Contributions to the Anatomy and Natural History of the Cetacea. By R.
KNOX, Esq., M.D., F.R.S.E. Communicated by the Secretary.
[Received Oct. 6, 1857.]
Part I. THE DOLPHINS.
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 vertebrae 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 vertebrae 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 vertebrae
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 Vertebrae in certain Cetacea._
(Cephalic vertebrae excluded.)
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| Authorities. |
| ---------------------------------------------------
| SPECIES. | CUVIER. RUDOLPHI. KNOX. J. HUNTER. HUNTER |
| | (Glasgow.)|
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| | | | | | |
|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. BALAENOPTERA. | | | | | |
|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. Phocaena_ | 66 | | 65 | 51 | |
| | | | | | |
|_D. Ebsenii._ Van| | | | | |
|Beneden | | | | | 90 |
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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
vertebrae 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 vertebrae; 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
vertebrae:--
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 vertebrae 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--
Vertebrae.
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 _a-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
_Balaenopterae_ 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 Phocaena. 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 vertebrae, 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 vertebrae 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 vertebrae 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
vertebrae, 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 vertebrae 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 arytaenoid 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 arytaenoid were present, and strong, but did not
extend so high as in man; the thyro-arytaenoid 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 valvulae 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 Phocaena_, 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 spinae) 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.
Part II. THE BALAENA WHALES, OR WHALES WITH WHALEBONE.
In February 1834 a young whale of the family of Balaena Whales was caught
near the Queensferry, in the Firth of Forth. One much larger had been
seen some time before, but escaped. I purchased it for dissection,
although I was aware that it was impossible for me, during the hurry of
the winter session, to devote much time to it. But I had able assistants
(Mr. Henry Goodsir, Mr. Edward Forbes, and my brother), from whom I
expected a good deal of aid. Some very beautiful drawings of this whale,
made for me by Mr. Edward Forbes and by my brother, are still in my
possession.
It was easy to see, by the dorsal fin and by the numerous plaits or
folds on the abdominal surface of the throat and chest, before any
dissection, that the specimen was a young Balaenopterous whale, differing
in a great many points from the true whale or _Mysticetus_: for, 1st,
the form of the head was entirely different; 2nd, it had a dorsal fin;
and, 3rd, occupying the lower surface of the throat and thorax were
numerous folds of the integuments. To this class of whales I have been
in the habit of giving the name of Rorqual, to distinguish them from the
other class of Whalebone Whales, the _Mysticetus_ both _borealis_ and
_australis_.
It appears from my notes, that at that time M. G. Cuvier considered the
species I now describe as identical with the Great Rorqual I had
described about two years previously; but I felt convinced then, as now,
that they form distinct species, and in this opinion some continental
anatomists seem to coincide.
Being persuaded that there was some inaccuracy in former drawings of the
species, I had the specimen suspended and drawn with great care by Mr.
Edward Forbes. This position explained the mechanism of the mouth,
showing its great size, even in the short Balaena Whales; its great
capacity in the _Mysticetus_ had never been doubted.
As to the species, the conclusion I arrived at was, that the specimen
belonged to that termed by Fabricius _rostrata_, and that individuals of
the species had been seen by John Hunter, Sir James Watson, and
Fabricius.
_Measurements._ ft. in.
Total length of the specimen 9 11
Circumference immediately behind the pectoral extremities 5 2
Circumference where the folds or rugae terminated 4 8-1/4
Ditto of the tail at its origin 1 5-1/2
Length from the back fin to the setting on of the tail 2 10
Length from the snout to the ear 3 0
Length from snout to nostrils 1 4
Length of lower jaw 2 3
Length of arm; inner side 1 3
Length from the angle of the mouth to the arm 1 3
Length from snout to arm 2 9
Length of tail in depth 0 11
Length of back fin at the base 0 8
Height of back fin 0 8-1/2
From top to tip of tail 2 8-1/2
Stomach:--1st compartment, in length 1 2
2nd compartment, in length 1 4
3rd compartment, in length 0 8
4th compartment, in length 0 7
5th compartment, in length 0 3
Spleen weighed 4 ounces; its length was 0 5
Liver, 9 lbs.
Small intestines, length 20 0
Large intestines, length 2 4
Kidney, weight 2-1/4 lbs.
Brain (including 2 inches of spinal marrow), 3-1/2 lbs.
Cerebellum, pons, and 2 inches of spinal marrow, 3/4 lb.
Great hemisphere of the brain measured 3 inches in
length, in breadth, 6-1/2; at the base, 8 inches.
Tuber annulare 0 1-2/8
Olfactory nerves, in length 0 1-1/2
Ditto, breadth 0 2-1/2
Skeleton:--Length of cranium 2 11
Greatest breadth between the orbits 1 3
Length of vertebral column 7 8
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