P. Martin (Peter Martin) Duncan.

Cassell's natural history (Volume 2) online

. (page 34 of 49)
Online LibraryP. Martin (Peter Martin) DuncanCassell's natural history (Volume 2) → online text (page 34 of 49)
Font size
QR-code for this ebook


Pacific has also been named Leopard Seal by Scammon. That to which the title Sea Leopard appears
most applicable is what De Blainville and others called the Small-nailed Seal (Phoca leptonyx), and F.
Cuvier the Narrow-muzzled Seal (Stenorliynclius leptonyx]. Its precise distribution is uncertain, but it
has been found on the coasts of Australia, New Zealand, Falkland, Campbell, Auckland, and Lord
Howe's Islands, and the Antarctic Ocean (on pack-ice). It may possibly be met with elsewhere, but
the foregoing are authenticated localities. Mr. A. W. Scott describes male and female stuffed speci-
mens in the Sydney Museum. The old male measures twelve feet in length ; the glossy spotted skin is
of a light silvery grey, with pale yellowish-white in patches, brought into relief by black-grey shading ;
its back and sides are darker, and belly lighter. The younger but adult female is seven feet long.
Her colour above is darkish-grey, almost black in the middle line, intermixed by narrow markings
of darker hue, and of yellowish-white, and the under parts without spots and also yellowish-white.
A specimen kept alive for several days at Port Jackson had a long muzzle, a long thin neck, and in its
liabits generally it resembled the Seal tribe. Dr. George Bennett killed a male in Shoalhaven River
(August, 1859), several miles above salt-water reach, which had a water-mole in its stomach. Dr. Knox
states that those he examined in New Zealand contained in their stomachs fish-bones, gulls' feathers,



80



Ommatophoca Eossii.



f Stenorhynchus leptonyx.



WEDDELL 1 S SEAL CRAB-EATING SEAL.



243




TEETH OF THE EA LEOPARD.



and seaweeds. Captain Musgrave, in his forced residence on the Aucklands, already referred to,

alludes to this animal as the Black Seal, and describes a fight between one and a Sea Lion (Otaria);

the flesh, he says, is rank. So far as his observations

go, they remain at these islands pretty nearly all the year

round, but others think that they occasionally migrate,

or, at least, at certain seasons less frequently approach the

land. The skull is remarkably elongated; the double- rooted

molar teeth are compressed and serrate, or have a three-

lobed crown, the middle being the longest. This animal

has but four incisors above and four below, and the canines

are of moderate dimensions. The nails on the hind feet

are almost absent.

WEDDELL'S SEAL.* A couple of stuffed specimens
and a few skulls of this Seal in the British Museum, and
a stuffed specimen in Edinburgh, are the sole material
on which this species is founded. Dr. R. Hamilton,

in the "Naturalist's Library," described the latter as the Leopard Seal (Phoca leopardina,
Jameson). Captain Weddell had brought it from the Southern Orkneys, and, according to him,
durino 1 life the animal is pale greyish above, yellowish beneath, and the back spotted with pale
white. Dr. Gray mentions the London male specimen as fulvous, with a blackish-grey line down
the back, the female and young corresponding to Captain Weddell's description. The distinction
between this and the last species is barely appreciable from their external coat, such differences as exist
being in the skull. Weddell's Seal, or, as Gray names it, the False Sea Leopard (Leptonyx Weddellii),
has a relatively shorter and broader skull, fuller in the brain-pan, largish orbits, and a weak lower jaw.
The molars are not tri-cusped ; the front one in each jaw is single-rooted, and the rest double-rooted.
The Antarctic Expedition brought home skulls, and skins and skulls were afterwards obtained by
Captain Fitzroy, R.N., from the River Santa Cruz, Patagonia. Neither they nor Weddell give us
any information respecting the life-habits of this animal. It will thus be seen that its geographical
area, and especially its geographical relations towards the previous species, are at present uncertain.
On account of the peculiarities of cranium and dentition, Gray forms it into a separate gemis.

THE CRAB-EATING SEAL, OR SAW-TOOTH STERRINCK OF OwEN.t The interest in this creature lies
probably not so much in the nature of its food as in the greater saw-like character of its molars, which
strongly resemble those of the fossil Zeuglodon, an animal of the Whale tribe. The Crab-eating Seal
inhabits an undefined area of the Antarctic Seas. Above it is of a nearly uniform olive colour, below
and the sides of the face yellowish-white, and there are a few often confluent spots of a light colour on
the flanks. The five-toed fore feet, whose wrist is said to be very short, are clawed, but the hind ones are
clawless. In number, the teeth agree with the Sea Leopard's ; though the first, second, and third front
upper and the first front lower molars are single-rooted, the rest double-rooted. Moreover, nearly all
the molar teeth have two or three cusps behind the middle strong conical lobe, while in front there is
usually only a single small conical elevation. Thus the hinder border of these molars is considerably
more saw-like than in the Sea Leopard. It differs also from the latter both in the lower jaw and upper
parts of the cranium, but more particularly in the nasal and facial regions. Little is known with
regard to its life-history.

The last three Seals some have considered under three distinct generic names, for reasons already
given. If importance be attached to the dentition, this separation is allowable ; but on the other
hand there are considerable resemblances which others regard as only of specific weight. The
generic term Stenorhynchus, first used by F. Cuvier in 1824 for the so-called Sea Leopard, and which
has been at times indiscriminately applied by different naturalists to all three animals with multi-
serrate crowned teeth, but here partially restricted to the first two, is a name well known and stili
applicable to one or other. Nevertheless, Lamarck, in 1819, had designated a genus of Crabs



Stenorhynch'us (Leptonyx) Weddellii.



t Lobodon carcinophaga.



244 NATURAL HISTORY.

Stenorhynchus, universally accepted, and also in current use up to the present time. Some confusion
having thus occasionally resulted, Professor Peters drew attention to the awkwardness of the
circumstance, and proposed that the term Ogmorhinus should replace Stenorhynchus, as applied to
the Seals ; Lamarck's name having priority being retained for the Crabs. This well exemplifies
one among the many difficulties and cross-purposes incident to nomenclature, &c., of Natural History,
where, in the vast array of names and facts presented, glaring discrepancies will arise, despite the
constant revision of those devoted to its study.



Before closing this chapter, there is one subject which I believe deserves mention, however
briefly. The enormous slaughter of the Seal tribe is a matter of serious consideration, if only in
a mercantile spirit. Among the sealers, neither sex nor age is spared, and therefore at the present
wholesale rate of destruction it is easy to foresee early comparative, if not absolute, extinction of the
tribe. Nothing can be clearer than the fact that since the Americans in their Alaska territory have
adopted the plan of killing a prescribed number annually of the young and male Seals only, in other
words, of protecting the breeding females, the Fur Seals have shown no tendency to diminution, but
rather an apparent increase. Nature has her limits, and the Seals have other enemies to contend
with besides man. Yet the latter, taking advantage of the maternal affections, and with the aid of
deadly firearms and the like, in a certain space of time commits more fatal havoc among them than all
their other foes combined. Several persons have urged a close-time. The fact is there are great diffi-
culties in the way of this, for even in well-protected British rivers and fisheries generally, Salmon
and others of the finny tribe are caught at forbidden times, in spite of Acts of Parliament and other
regulations. Who is to watch the sealers in far-off inhospitable climes 1 Certainly in the Northern
sealing-grounds the departure of the ships could be made somewhat later, as has, indeed, to some
extent been done, but of course at the risk of a diminished catch. In the long run beneficial results
doubtless will follow. But the plan most applicable to both Northern and Southern Seal-capture
would be the insistance of the simple rule of sparing the breeding females whenever possible. If our
merchants at home would take the matter in hand, and, but for a few years, refuse to receive
female skins, the sealers would be practically forced, and in fact find it to their benefit, to look to their
interests from a more humane point of view.

JAMES MURIE.




245



ORDER CETACEA. WHALES.

Whales Vulgar Notions Characteristics External and Internal Larynx Tail Skeleton Classification -THE TOOTHED
WHALES ZEUGLODONS SQUALODONS PHOCODONS RIVER DOLPHINS Susu, OK GANGETIC DOLPHIN Description
Habits Teeth INIA PONTOPORIA ZIPHIOID WHALES CUVIER'S WHALE VAN BENEDEN'S WHALE SOWERBY'S
WHALE NEW ZEALAND BERARDIUS BOTTLEHEAD, OR COMMON BEAKED WHALE SPERM WHALES, OR CACHALOTS
SPERM WHALE Description Range Fishery Incidents of the Chase Habits Harpooned Treatment of the
Carcass SHORT-HEADED WHALE, OR SNUB-NOSED CACHALOT DOLPHINS CAAING, OR PILOT WHALE Risso's
GRAMPDS COMMON PORPOISE KILLER WHALE, OR ORCA Ferocity TRUE DOLPHINS COMMON DOLPHIN BOTTLE-
NOSE DOLPHIN WHITE WHALE NARWHAL THE WHALEBONE WHALES Whalebone GREENLAND, OR RIGHT
WHALE BISCAY WHALE JAPAN WHALE CAPE WHALE SOUTH PACIFIC WHALE Description of the Greenland
Whale Their Food and Mode of Feeding Habits Hunting Treatment of Carcass HUMP-BACKED WHALES
FIN WHALES, OR RORQUALS SIBBALD'S RORQUAL SULPHUR-BOTTOM WHALE COMMON RORQUAL, OR RAZOR-BACK-
LESSER RORQUAL Concluding Remarks.

THE Whales form one of the most extraordinary groups of the Mammalia, for they are warm-blooded,
air-breathers, and sucklers of their young, and are most strangely adapted for life in a watery element.
Oddly enough the term " Fish " is still applied to them by the whalers, though they have nothing in

common with these creatures save a certain similitude in shape.
The vulgar notion of a Whale is an enormous creature with an
extremely capacious mouth, but the fact is that many of the
Cetacea are of relatively moderate dimensions, though doubtless,
on the other hand, the magnitude of some is perfectly amazing.
Thus, in size they are variable as a group, a range of from five
or six feet (equal to the stature of man) to seventy or eighty
feet giving sufficiently wide limits. With certain exceptions,
notwithstanding length, an average-sized Whale by no means
conveys to the eye the same idea of vastness, say for instance,
as does an Elephant. The reason is that most Cetaceans are of
a club shape, the compact cylindrical body and long narrow
tapering tail reducing the idea of size. The head is in such
continuity with the body that of neck there seems nothing. In
some there are upright fleshy back fins ; in others these are
wanting. The gristly caudal fin is horizontal and not upright or
rayed like a fish's. The body is smooth and devoid of hair.
The eye is remarkably small and without eyelashes, and the ear
orifice is so diminutive as to seem deficient. The head is either
rounded, massive, or has a long snout. There are no hind limbs,
and only in the enormous Whalebone Whales have the
rudiments of any been found. Small pelvic bones, how-
ever, are present, embedded in the flesh at the setting-
on of the tail. The fore-limbs, which are ordinarily
termed flippers, have the usual bones extremely
broadened and flattened ; the free part equivalent to
the hand being encased in a rigid or stiff nailless
membrane ; and in a few instances the phalanges are
exceedingly numerous, producing a long-fingered pecu-
liarity met with in no other Mammal. The two
mammae adjoin the pelvic bones, the nipples being sunk
in slits. In one section only, the Mysticete, is the
mouth very large. In them great plates of the so-called
whalebone, a homy substance, occupy the place of teeth.
In another section, the Denticete, with moderate-sized
mouth, teeth are present in few or greater numbers.
These are implanted in simple sockets without successors
i.e., there is no milk and adult dentition as in the foregoing orders.




STOMACH OF PILOT WHALE. (After Mu

ce, oesophagus, or gullet; 6, bile duct ; i, intestine ;
l,l*,2, (,4, represent the various chambers, the arrows
denoting the direction food takes in passing onwards.




VPPER SURFACE OF THE BRAIN OF THE PORPOISE.

(After Leuret and Gratiolet.)



The tongue cannot be thrust



246



NATURAL HISTORY.



oiit. The gullet is narrow in some, and wider in others, but the stomach in all is peculiar, and composed
of three or more chambers with narrow passages between; in this respect corresponding to that of Sheep
and cattle. The intestines are long, glandular, and full of little pouches. There is no gall-bladder. The
brain is of considerable calibre, globular, and remarkably convoluted. The
heart is distinguished only for great size, and the blood vessels are exceedingly
capacious and numerous. But what is remarkable in the vascular system is
a great mass composed of enormous numbers of minute tubes, forming a so-
called rete mirabile, like that formerly described in the Lemurs. It is situated
within the body along the inside of the spine. This, in the Whales, has been
supposed to be a respiratory provision to enable them to remain long sub-
merged ; but I have shown elsewhere that its connection with the glands of
the lymphatic system may render it functionally subservient to nutrition and
purification of the blood. The lungs are large, but the most extraordinary
features are the larynx and nasal passages. The nostrils, often a single
crescentic aperture, open right on the top of the head, except in
the Sperm Whale, and not in front as in all other Mammalia. In
some thei % e are small pouches near the orifice or blowhole of
.c uncertain use. In front of the larynx of man we all know

there is an elastic lid, the epiglottis,
which folds over and protects the i
passage as food is swallowed. The side
cartilages constitute the walls of the
organ of voice, and protect the vocal
cords. Now, in the comparatively
*53^:j mm voiceless Whale the cartilages including

the epiglottis form a long rigid cylin-

INTERIO* VIEW OF LARYNX OF RISSO'S GRAMPUS. (After Murie.) ^^ ^^ ^^ g ^.^ ^ ^

Ep, epiglottis;. vc, vocal cord; s, sac; c, cartilage; gl, gland; tr, trachea. The arrows ,1 i /. ,1 i ,

show direction of air-currents In ingress and egress. passage at tile DaCK Ol tile palate in

continuity with the blowhole. It is

there held in place by a muscular ring. With the larynx thus retained bolt upright, and the
blowhole meanwhile being compressed or closed, the Cetacean is enabled to swallow food under
water without the latter entering the lungs. Respiration, " blowing " or " spouting," takes place
at intervals as the animal reaches the surface, and the volume of air thrown up along with sur-
rounding moisture and condensed vapour in some rises in a great jet. The flesh of the body





SKELETON OF SPERM WHALE. (After Flower.)
8, Spermaceti Cavity ; n, Nasal Passage, in dotted line ; &, Blowhole.

terminates in long cords of tendon running to the tip of the tail. These tendons, like a te]egraphic
cable, bound together in the smallest compass, are moved by the enormous fleshy masses of the
body, and thus their vast force is conveyed to the caudal appendage, whose great power as a pro-
pelling agent (and even a destructive one) enables the Whales to be truly roamers of the sea. Save
the tail and flippers, the body is covered by a dense layer of fat, the blubber. In the skeleton the
neck-bones are often soldered into one or two separate pieces, rigidity being needful in front, while the



THE SEAL-TOOTHED WHALES. 247

remaining vertebrae, tapering to exceedingly small bones in the tail, are each separated by thick elastic
fibro-cartilaginous cushions, thus giving great flexibility behind. The breast-bone is often in a single
flat piece. The skull is greatly modified and by no means uniform throughout the group. Among
the Dolphins and others (Delphinidse) it is strangely distorted, so that the one side does not agree
with the other. The upper jaw-bones (maxillce) and the pair of bones above and between them
(premaxillcK) are unusually produced, and this production in front, with corresponding extension of
lower jaw, gives a lengthened facial region and snout accordingly. The bones surrounding the occiput
and brain-pan are directed upwards, the former occasionally forming a great horseshoe crest. The
bony nasal passages instead of coming forward lead nearly direct upwards towards the summit of the
cranium, nasal bones themselves being all but absent. The orbits are often small and open behind.
Curiously enough, though deficient in ears, the interior tiny ear-bones of other Mammals are in the
Whales great massive structures and exceedingly dense, so much so that they are frequently preserved
fossil when other osseous structures are destroyed.

Cetacea have been a troublesome group to unravel, being ocean-dwellers, and many of them huge
brutes. To study them in the live state has been difficult, and their carcases when captured or stranded
on shore are as unmanageable for purposes of examination. As to their classification the two sub-
orders Denticete, Toothed Whales, and Mysticete, Whalebone Whales are universally accepted. As
regards the families, the main groups are tolerably well agreed upon, though differently named by
authorities. Among the sub-families, the genera and the species, there is less unanimity. The
grouping of the living forms proposed by Professor Flower is in Great Britain more frequently
adopted, while MM. Gervais and Yan Beneden, in their great work on " Osteographie des Ce'taces,"
have collated the living and fossil forms. Some species and genera of Whales are restricted within
given areas, as are the Seals, but of the habitat of many others in truth so little is known that no
defined limit can be assigned. The great majority are migratory ; some are gregarious, others more
solitary in disposition. A few are quite fluviatile ; but most are found in the high seas. Following
the above primary divisions, we give precedence to

THE TOOTHED WHALES (DENTICETE.)

Except the possession of teeth, no other available common character need here be given.

THE SEAL-TOOTHED WHALES (PHOCODONTIA OR ZEUGLODONTIA).

We begin with these, as they are supposed by some authorities to be intermediate between the
Seals and Whales. This extinct family, judging from the various mutilated remains found, comprised
several different
genera. The most
notable of these
are Zeuglodon,
Squalodon, and
Phocodon. The
ZEUGLODONS may
have attained a

RESTORATION OF SKULL (A). AND TOOTH (B) OF ZEUGLODOX. (After Gaudru.)

length of fifty or

sixty feet. Their vertebral column was cetacean in character, but the neck-bones were separate,
though considerably flattened from before backwards. Some assert that their skull bore resem-
blances to that of the Seals in several respects. Their brain-cavity undoubtedly was remarkably
small, and relatively less than that of known Whales ; but the supposed Seal-like skull structure
is open to question. The teeth were of two kinds : those in front being conical, pointed, and
lengthened; and those behind laterally compressed, serrate, and double-rooted. The dental
formula is stated to have been Incisors, |=| ; canines, ^ ; molars, || = 36. Hind limbs may
have been absent, but the fore limbs suggest rather than furnish precise data showing approxi-
mation to the Seals. The SQUALODONS are known chiefly from the skull, which, as a whole, has
strong resemblances to those of the curious Amazon Dolphins, called Inia and Pontoporia, but the
dentition, however, agrees rather with that of the Dolphin of the Ganges, Platanista. They possessed





248 NATURAL HISTORY.

a long, narrow snout, but 110 special crest on the summit of the head, and the blow-holes were situate
as in the foregoing three last-mentioned living genera. Van Beneden has given the following formula
of the dentition : Incisors, jj=| ; canines, ^ ; molars, J|=i| = 60. Their teeth in most respects re-
sembled those of the Zeuglodons. Much less is known of the PHOCODONS, our information regarding
them being chiefly derived from the teeth. These latter were not unlike the rearmost of those of the
Zeuglodons and Squalodons. The Zeuglodons have been found in the Eocene and Miocene strata of
North America. The first remains from Alabama were considered by Dr. Harlan to be those of an
enormous reptile (Basilosaurus), but Professor Owen proved their Mammalian character from the
teeth being implanted in distinct sockets. The Squalodons and the Phocodons have not only been
found in the United States, but in Australia, and in France, Belgium, Austria, Italy, and England.
Of course nothing is known respecting their habits other than what may be legitimately inferred
from their skeletal peculiarities. To all intents and purposes, so far as we know, the balance lies in
favour of their having had the habits of Whales. They may have been river-frequenters, and judging
from the dentition their food woiild be similar to that of the Ganges and Amazon Dolphins.



THE RIVER DOLPHINS (PLATANISTID^).

Three living forms come under this heading, which, however, barely present such characters in
common as to render them a compact group ; and some authorities even incline to regard them as
representative of sub-families. As in the Seal-toothed Whales their neck vertebrae are separate.

THE Susu, OR GANGETIC DOLPHIN.* This remarkable Cetacean is never found in the salt water,
or at best only in the brackish water of the Sunderbunds ; its habitat being the rivers Ganges and
Indus from their mouths upwards, and their various tributaries almost to the mountain ranges in the
north. Specimens have been got at least 1,000 miles beyond Calcutta. It measures from six to
twelve feet in length, and in colour is entirely sooty black. Its long body has a moderate girth, and
just behind the middle of the back there is a slight elevation which can barely be called a fin. The
tail is broadish ; the flippers are short, very broad, fan-shaped, and not pointed as in most Whales.
The head is globular, with a long, narrow, spoon-shaped snout. The opening of the blow-hole, unlike

that of other Whales,
excepting the Inia, is
not transverse, but a
single longitudinal slit.
The eye externally,
situated above the angle
of the mouth, is so
diminutive as barely to
be visible. We may
compare the Susu to the
Mole in this respect, for
in an adult eight feet
long the whole of the
eyeball is no bigger than
a pea in size. Small
though this eye is,
nevertheless it is perfect
in lens and humours, &c.
The ear-orifice behind
the latter may be com-
pared to a pin-hole. The
narrow rostrum of the

upper and of the lower jaw is implanted with a series of teeth, more pointed and conical in front, and
narrower and laterally flattened in those behind. In the young animal the difference between the

* Platanista ganc/etica.




SHE (A) AND UPPER (B) VIEWS OF SKULL; (c) REARWARD AND (n) FORWARD TOOTH OF
YOUNG OF GANGETIC DOLPHIN. (After Gervais and Yan-Beneden.)



THE SUSU, OS GANGETIC DOLPHIN.



249



anterior and the posterior teeth is exceedingly marked in size, the former being very long, the latter
very short, while as age advances quite the reverse is the case. The back teeth also wear down very
considerably in the crown, and increase in breadth in root-substance ; indeed, as Dr. J. Anderson
has shown, the true dental material is worn away, and finally nothing but bone is left. The head
of the male is about two-thirds the length of that of the female, and in both its point is slightly
upturned. The apparently rounded skull behind the snout has broad thick zygomatic arches, and
above and in front of these the cheek-bones (maxillae) each send forwards and inwards a great
roughened sheet of bone or crest, which forms a kind of open helmet. In the large hollow between
these bony plates, and somewhat behind, are situated the nasal orifices, which are slightly awry.

The Susu frequents the deep reaches and creeks of the river, occasionally coming to the surface to




GANGETIC UOLl'HIX.

blow, and although often heard are but seldom captured. Ordinarily their movements are slow, but
at times they seem exceedingly active. Their food is chiefly fish, shrimps, &c., which they grovel for



Online LibraryP. Martin (Peter Martin) DuncanCassell's natural history (Volume 2) → online text (page 34 of 49)