The Cambridge Natural History Part 29

The genus _Berardius_[250] differs from _Mesoplodon_ by its rather more symmetrical skull, of which the vertex is formed by the nasals. The mesethmoid is only partly ossified. The teeth are two on each side of the mandible, with their apices directed forwards. The vertebral formula is C 7, D 10, L 12, Ca 19.

_B. arnouxi_, from the seas of New Zealand, is the only species of this genus which is well known. It is 30 or 32 feet in length, and is of a velvety black colour, with a greyish belly. Instead of lowing like a cow, this Whale has been described as "bellowing like a bull"! A singular and somewhat inexplicable fact has been stated of this species. The teeth were said to be protrusible, and Sir James Hector stated that the teeth were imbedded "in a tough cartilaginous sac which adheres loosely in the socket of the jaw, and is moved by a series of muscular bundles that elevate or depress it." Sir William Flower justly observed that these statements "accord so little with anything hitherto known in mammalian anatomy that further observations on the subject are extremely desirable." Like other Ziphioids, _Berardius_ feeds mainly, if not entirely, upon cuttle-fish, a prey eminently suited to their almost toothless mouths. It is not known whether _Berardius_ has the {369} Ziphioid grooves upon the throat. Nothing is known of the structure of the internal viscera of this Whale. It appears not to be really limited to the region of New Zealand, as is often stated, for Malm has lately described a skull (_Berardius vegae_) from Bering's Straits.[251]

_Mesoplodon_[252] is a world-wide genus embracing a number of species; on the lowest estimate seven species can be distinguished, and Sir W. Flower would add two more. These are moderate-sized Whales, 15 to 17 feet in length. In the skull the mesethmoid is ossified; the nasals are sunk between the upper ends of the premaxillae. There are but a single pair of teeth in the mandible attached to nearly the middle of its length (whence the generic name). The vertebral formula is C 7, D 9 or 10, L 10 or 11, Ca 19 or 20. The sternum consists of four or five pieces. The amount to which the cervical vertebrae are fused varies; but some are always fused.

The only species which has ever been stranded on the sh.o.r.es of this country is _M. bidens_, an example of which was described many years ago as the "Toothless Whale of Havre"; it was an old animal which had probably lost its teeth. Nevertheless it received the separate generic and specific name of _Aodon dalei_. The animal lived for two days out of the water, and made a sound like the "lowing of a cow." An instance of the rarity of the Whales of this genus is afforded by _M. europaeus_, of which only a single skull is known; this was extracted from a dead body, found floating, about the year 1840. It has never appeared since. _M. layardi_ is remarkable on account of the very large size of its strap-shaped teeth; these curve over the upper jaw in such a way as to prevent the animal from fully opening its jaws. The case is curiously paralleled by the Sabre-toothed Tiger. This species is antarctic in range. From the opposite extremity of the globe comes _M. stejnegeri_, again known by but a single skull. It is singular on account of the large size of the brain case, and is a native of Bering's Straits. _M. hectori_ has its two teeth situated quite at the extremity of the mandible, and in this feature approximates to the genus _Berardius_. It was, indeed, confounded with that genus by one naturalist. {370}

_Ziphius_ is a genus which is also of world-wide range. Here again the number of species is at present merely a matter of opinion. The prevalent impression, however, is that but a single species exists, which will therefore have the name of _Z. cavirostris_. The genus (and for the matter of that the species too) may be thus characterised in comparison with its allies. The mesethmoid is ossified as in _Mesoplodon_, but the nasals joined together form the vertex of the skull. There are two teeth near the symphysis of the mandible, besides the usual small and "functionless" teeth in the upper jaw. The vertebral formula is C 7, D 9 or 10, L 11, Ca 21.

The throat of a _Ziphius_ from New Zealand was described by Messrs. Scott and Parker[253] as having three grooves on each side. Whether this form is the same as von Haast's _Z. novae zelandiae_ is a matter of doubt; but the individual to which his name has been applied was 26 feet long, and had but a single groove on each side. Even in the external characters of many Whales many points require clearing up. Our knowledge of _Ziphius_ dates from the year 1804, when a skull "completely petrified in appearance" was picked up upon the Mediterranean coast of France, and described by the great Cuvier. It was forty years before another specimen was found. In the New Zealand specimen of von Haast already referred to, the body was scored by numerous lacerations. These wounds may have been due to fights among the Whales themselves; the forwardly-situated teeth would be capable of inflicting such wounds. But it has also been stated that the armed suckers of gigantic cuttle-fish are responsible for these scratches.

_Hyperoodon_ is the most easily-distinguishable genus of Ziphioid Whales.

Its characters are the following:--The skull has enormously-developed maxillary crests in the adult male; the mesethmoid is not fully ossified.

There is but a single tooth to each ramus of the lower jaw, besides, of course, the usual small teeth in the upper jaw. The vertebral formula is C 7, D 9, L 9, Ca 18. The cervicals are fused into one ma.s.s, more or fewer being free in other Ziphioids. The sternum consists of three pieces only, the last of which is bifid posteriorly.

The name _Hyperoodon_ was given to this Whale by Colonel Lacepede on account of the rough papillae upon the palate, which {371} were mistaken by that observer for teeth. It is curious that the name is really appropriate in spite of this mistake, though of course it would be so to all the Ziphioids. In more than one feature this genus comes nearest of all the Ziphiinae to _Physeter_. Its enormous maxillary crests are paralleled in that Whale; but in _Hyperoodon_ their great thickness contrasts with the thinness of those of the Cachalot. The correspondence in the attachment of a rib to its vertebra by both heads is noteworthy. It is remarkable that in this particular _Hyperoodon_ is more like _Physeter_ than the supposed nearest ally of the latter--_Kogia_.

Of this genus two species are known. The best known is the common northern _H. rostratum_ (with many aliases); the second species from the southern hemisphere, _H. planifrons_, is only known from a single water- and pebble-worn skull. Its identification, however, depends upon the known accuracy of the late Sir William Flower.

The northern species (_Hyperoodon rostratum_) has often been recorded upon our own coasts; the first record of the stranding of this Whale was in the year 1717. In that year an example was found at Maldon, in Ess.e.x. Like the Beluga, _Hyperoodon rostratum_ gets lighter in colour with advancing years.

The young are black; the old animals pale brown with some white about them.

The under surface, however, is always greyish white. The length of this Whale reaches to at any rate 30 feet. But John Hunter had a specimen which he believed to be 40 feet in length. The specimen, however, consisted only of a skull, so that error might have crept in. It has already been mentioned that the old males have enormous maxillary crests. According to M. Bouvier, who has lately made an exhaustive examination of the anatomy of this Whale,[254] the females occasionally exhibit the same crests, which are thus presumably of the nature of spurs sometimes seen in old females among the Gallinaceous birds. The number of grooves upon the throat is in dispute in this Whale as in _Ziphius_. One pair is the usual allowance; but Kukenthal found four in some embryos studied by him. Attention has already been called to the voice of Ziphioid Whales. _Hyperoodon_ neither "lows"

nor "bellows," but "sobs"! _Hyperoodon rostratum_ is a gregarious Whale, going about in herds, or "gams" as they should technically be termed, of four to ten or even fifteen. This Whale {372} can leap right out of the water, and while in the air can turn its head from side to side, a capability which has not been mentioned in any other Whale. It can also stay under water for an unusually long period. Captain Gray,[255] who has made an accurate study of this species, states that so long a period as two hours is the limit of endurance; this event occurred in the case of a harpooned Whale.

FAM. 2. DELPHINIDAE.--This family, which includes the greater number of Cetacea, may thus be characterised:--Whales of small to moderate size.

Teeth as a rule numerous, and present in the upper as well as in the lower jaw. Maxillae without large crests; the pterygoids, often meeting in the middle line, enclose an air s.p.a.ce open behind. The anterior (five to eight) ribs are two headed, the posterior with tubercular head only. The sternal ribs are ossified.

The Dolphins and Porpoises, as already stated, embrace the greater number of existing species of Whales. Sir W. Flower and others who have followed him, allow nineteen genera. But as to the exact number of known species there is much uncertainty. That very careful observer, Mr. True, considers[256] that there are fifty which demand recognition. As many as one hundred have received names. The matter is one which is perhaps barely ripe for decision. All the Dolphin tribe are, for Whales, smallish animals.

The Killer Whale, _Orca_, is the only genus (or species?) which usually attains to more than moderate bulk. The rather mysterious _Delphinus coronatus_, 36 feet in length, of M. de Freminville, would seem to be a Ziphioid; it was described as having a very pointed beak, and as having the dorsal fin situated near the tail; such characters suggest a _Mesoplodon_.

The genus _Delphinapterus_, the Beluga or White Whale, consists of but a single species, though as usual more than one name has been given to supposed different species. It is characterised as a genus by the following a.s.semblage of structural features:--It has only eight to ten teeth occupying the anterior part of the jaws only. All the cervical vertebrae are free and unjoined. The vertebral formula is C 7, D 11 (or 12), L 9, Ca 23. The pterygoids are wide apart, though they converge as if about to meet at their posterior ends. There is no dorsal fin. The colour is white.

{373}

The Beluga is a northern species purely. The reputed form, _D. kingii_, was said to come from Australian seas; but there seems to have been an error in this statement. It is interesting to note that the white colour, so characteristic of the genus and species, is not found in the young, which are blackish. They gradually pale as they advance towards maturity.

_Delphinapterus leucas_ reaches a length of 10 feet, and like other Porpoises will ascend rivers in search of food. It is said to be specially addicted to salmon. Among the contents of the stomach have been found quant.i.ties of sand. But this habit of swallowing sand or pebbles has been noted in other Whales. Whether it is or is not accidental (taken in with ground-living food), it seems hardly likely that it is used for purposes of ballast! The Beluga has a voice; but the name "Sea Canary" is hardly suitable to it. A specimen of this species, recently described from the sh.o.r.es of Scotland (it is often thrown up upon our coasts), which had got entangled in the stakes of a new net, was regarded by the natives, on account of its white colour, as a ghost. Externally, besides its colour, the Beluga is remarkable for possessing a distinct neck, which is correlated of course with the freedom of the cervical vertebrae, and is also seen in Platanistidae.

The Narwhal (_Monodon_) is closely allied in structure to the last genus.

It has the following anatomical characters:--The teeth are reduced to a single "horn" in the upper jaw, which is rudimentary in the female. The neck vertebrae are free. The vertebral formula is C 7, D 11, L 6, Ca 26.

The pterygoids are as in _Delphinapterus_, and, as in that genus, there are no hairs upon the face or dorsal fin.

This genus is of course most obviously characterised by the twisted tusk of the male, which is occasionally double. This tusk has given to the only species of the genus, _M. monoceros_, both its generic and specific name.

The animal has a spotted colour; but, as in the case of the Beluga, old animals tend to become white. The use of its horn to _Monodon_ has been debated. In the first place it is clearly a secondary s.e.xual character. The males have been observed to cross their horns like rapiers in a fencing match. It may be that they are used in more serious combats. An ingenious suggestion is that the long and strong tusk enables its possessor to break the thick ice and {374} make a breathing hole. A third suggestion is due to Scoresby, who was led to make it from having taken out of the stomach of a Narwhal a large skate. He held that with its tusk the Whale empaled the fish and then swallowed it. The Narwhal is not large, 15 feet or so in length. But Lacepede, who was apt to compile with lack of discrimination, speaks of 60 feet long Narwhals. _Monodon_ is purely Arctic, and but three or four specimens have ever been cast up on our sh.o.r.es.

Of true Porpoises, genus _Phocaena_, there are apparently several species.

The genus itself has the following characters:--The teeth are sixteen to twenty-six on each half of each jaw; their crowns are compressed and lobed.

The pterygoids do not meet. The dorsal fin has a row of tubercles along its margin.

The Porpoise of our coasts, _P. communis_, is a smallish species 6 to 8 feet in length. There are two to four hairs present in the young; its colour is black, generally lighter on the belly. The first six cervical vertebrae are fused. The ribs vary in number from twelve to fourteen pairs.

It is a gregarious Whale, and will ascend rivers; it has been seen for example in the Seine at Paris. The name Porpoise is often written Porkpisce, which of course shows its origin. Very conveniently it was regarded as a fish, and therefore allowed to be eaten in Lent. The celebrated Dr. Caius, a gourmet as well as a physician and the refounder of a college, invented a particular sauce wherewith to dress this royal dish.

Some time since Dr. Gray described a Porpoise from Margate as a distinct species (see p. 342) on account of the tubercles, which are now known to be a generic character.

Dr. Burmeister's _P. spinipennis_ seems, however, to be really distinct. It was captured near the mouth of the Rio de la Plata. It is more tuberculated on the fin and back, and has fewer teeth (sixteen as against twenty-six).

Mr. True's _P. dallii_ of the Pacific (where the Common Porpoise also occurs) is characterised chiefly by its very long vertebral column, consisting of ninety-eight vertebrae; there are only sixty-eight in the other species. The Eastern genus _Neomeris_ is placed with _Phocaena_ by Dr. Blanford. It practically only differs by the absence of a dorsal fin.

It is only about 4 feet long, and inhabits the seas of India, Cape of Good Hope, and j.a.pan. The one species is called _N. phocaenoides_.

The genus _Globicephalus_ is to be defined thus:--Teeth {375} seven to twelve on each side, confined to anterior end of jaws. Skull raised into a prominence behind the blow-hole; pterygoids large and in contact. Pectoral fin long and falcate; dorsal fin present. No beak. Vertebral formula C 7, D 11, L 11 to 14, Ca 27 to 29. Six pairs of the ribs are two-headed.

The best known species of the genus is the Ca'ing Whale, _G. melas_.[257]

This animal reaches a length of 20 feet, and is thus one of the largest of the Delphinidae. It is gregarious and was, even is now, much hunted in the Faeroe Islands. Its sheep-like habits (embodied in one scientific name _deductor_) enable it to be easily driven on sh.o.r.e in herds, which are then harpooned. The foetus of this Whale has a few hairs; the number of phalanges in the two middle digits is very great, as many as eleven to fourteen. _G. scammoni_, _G. brachypterus_, and _G. indicus_ are other reputed species of the genus allowed by True and Blanford.

_Grampus_ is a genus allied to the last. It has no teeth in the upper jaw, and but three to seven in the lower jaw, near the symphysis of the mandible. The pterygoids are in contact. There is no beak, and the pectoral fin is long. There are twelve pairs of ribs, of which six are two-headed.

Apparently there is but one species, _G. griseus_, known as "Risso's Dolphin." It is a Mediterranean and Atlantic form, and is not common.

The genus _Orca_ has as characters:--Teeth ten to thirteen, long and strong. Pterygoids not quite meeting. Vertebrae C 7, D 11 to 12, L 10, Ca 23. The first two or three fused. The dorsal fin is long and pointed.

Of this genus there may be more than one species; but the best known is the Killer Whale, _O. gladiator_ (Fig. 180, p. 341), often spoken of as the "Grampus."[258] It is marked with contrasting bands of white or yellow upon a black body-colour. The animal grows to a considerable length, as much as 30 feet. _Orca_ is a powerful and rapacious Whale; and Eschricht has stated that from the stomach of one, thirteen Porpoises and fourteen Seals were extracted. They will also combine to attack larger Whales, and Scammon has related how he witnessed such an onslaught upon a Californian {376} Grey Whale. "Belua truculenta dentibus," observed Olaus Magnus of this Cetacean.

The high dorsal fin has been much exaggerated in old drawings; it has been even represented as strong and sharpened at the end, so as to be capable of ripping open the belly of a Whale. The fact that it sometimes lies over a little to one side is responsible for another anecdote: that an example of this Whale was seen to retire with a couple of Seals tucked away under the flippers, another grasped by the dorsal fin, and a fourth in the mouth!

"When an Orca pursues a whale," wrote Dr. Frangius, "the latter makes a terrible bellowing like a bull when bitten by a dog." It is probable, according to F. Cuvier, that this Whale is the "Aries marinus" of the ancients, certain bands of white upon the head giving an impression of curved horns. It may also be the "horrible Sea-satyre" of Edmund Spencer.

Allied to _Orca_, but distinguishable from it by some rather minute peculiarities, is _Pseudorca_. It may be thus defined:--Teeth eight to ten, much like those of _Orca_. Dorsal fin rather small, falcate. Vertebral formula C 7, D 10, L 9, Ca 24. Six or all the cervicals united. The curious fact about this Whale, which embraces only a single species, _P.

cra.s.sidens_, is that it was first known in the fossil condition from remains discovered in the fens of Lincolnshire. An important day for cetologists was that on which a whole herd entered the Baltic and furnished material for a better study of this Whale. It is not, any more than its near ally _Orca_, confined to northern seas; for several examples, at first relegated to a distinct species (_P. meridionalis_), have been obtained from the seas round Tasmania.

_Orcella_ (which has been written _Orcaella_) has fourteen to nineteen small sharp teeth in each half of each jaw. The pterygoids are widely separate. The dorsal fin is small and falcate. The vertebral formula is C 7, D 14, L 14, Ca 26. Seven ribs are two-headed, and five of them reach the sternum.

This genus contains but a single species, _O. brevirostris_, which is both marine and fresh-water in habit; it occurs in the Indian seas, and in the Irrawaddy even as far up as 900 miles from the sea. Some regard the fresh-water individuals as a distinct form, _O. fluminalis_.

_Sagmatias_ is a genus known only from a skull, which is remarkable for the elevation of the premaxillae into a crest; the {377} pterygoids are short, and there are thirty-two teeth in each half of each jaw.

_Feresia_ is known from two skulls which are provided with ten to twelve teeth in each half of each jaw. It is intermediate between _Globicephalus_, _Grampus_, and _Lagenorhynchus_, according to Sir W. Flower.

The genus _Delphinus_ contains the Dolphin, _D. delphis_.[259] The genus may be characterised as follows:--Teeth small and numerous, forty-seven to sixty-five. Vertebral formula C 7, D 14 or 15, L 21 or 22, Ca 30 to 32. The atlas and axis are fused, the rest free. The palatal border of the maxillae is deeply grooved. The fins are falcate; the beak long and distinct.

The Common Dolphin of the Mediterranean shows so many variations of colour, slight differences in the proportions of the bones of the skull, and in the number of the teeth, that it has been divided up into at least seventeen "species." But M. Fischer, who has studied many of these forms, does not admit them, and most students of this group of mammals follow him in the matter. The Dolphin is and has been the most familiar of Cetaceans; in consequence it has acc.u.mulated much anecdote of a mythical character. The extreme intelligence and goodwill towards man a.s.signed to this creature by the ancients are possibly due to the anomaly of a creature ostensibly a fish showing many of the characters of higher animals. Its unfishlike intelligence baffled the early observers, who at once endowed it with especially advanced attributes. Hence the stories of Arion and others. The leaping of the Dolphin out of the water is exemplified in many Mediterranean coins and coats of arms; the heraldic dolphin is represented with an arched back as in leaping. The Dolphin reaches a length of some 7 feet, and appears to be world-wide in range. Possibly distinct is _D.

longirostris_, characterised, as the name denotes, by the very long beak; it has also more teeth and is a native of Malabar. _D. roseiventris_ again may be a third species of _Delphinus_. It comes from Torres Straits, and has the under parts rosy in colour.

The genus _Prodelphinus_ has, like _Delphinus_, a distinct beak; but it has not the grooved maxillaries. No other character of importance appears to separate it from _Delphinus_. {378}

The genus consists of some eight widely distributed species, which are none of them large Dolphins.

_Lagenorhynchus_ has the following a.s.semblage of characters:--Head with short, not very distinct beak. Dorsal and pectoral fins falcate. Teeth small, twenty-two to forty-five in each half jaw. Vertebrae ranging in number from seventy-three to ninety-two. Pterygoid bones either in contact or separate. There are fifteen or sixteen pairs of ribs, of which six are two-headed. Of this genus Mr. True allows eight species, which have been increased by a ninth since the publication of his "Revision."[260]

Two species of _Lagenorhynchus_ are known from our coasts; the rest are mainly southern in range. The British species are, firstly, _L.

albirostris_, a Dolphin of some 9 feet in length. It has a large number of vertebrae, ninety-two in number. _L. albirostris_ is a rare species, the first record of its occurrence on these sh.o.r.es being in 1834. Since that date some eighteen individuals have been shot or stranded on the sh.o.r.es of the British Isles. The second British species, _L. acutus_, differs in colour from the first. As in the last, the upper parts are black and the under parts white; but in _L. acutus_ there is also a stripe on the flanks, brownish in colour. It has fewer vertebrae, not more than eighty-two.

The next genus of Dolphins, _Sotalia_, is characterised by--Teeth tolerably large, twenty-six to thirty-five. The vertebral formula is C 7, D 11 or 12, L 10 to 14, Ca 22. The pterygoids are not in contact in the middle line. It has a distinct beak.

Of this genus there are some six species (the exact number, as in so many other genera, cannot be positively a.s.serted), most of which are fluviatile or estuarine in habit. They are also on the whole characterised by their pale, if not actually white, coloration. _S. sinensis_ of the Amoy is white with pinkish fins. _Sotalia guianensis_ is American as its name denotes. It is figured by van Beneden as of a pale brown colour. It is very abundant in the Bay of Rio de Janeiro, and has the reputation of being a friend of man like some other Dolphins. The natives hold that it will bring to sh.o.r.e the bodies of drowned persons. The most singular species of the genus is that recently described by Professor Kukenthal as _S. teuszii_.[261] This animal is purely fresh-water, being found in {379} the Camaroon river, where it is extremely rare. The nostrils (blow-hole) are prolonged into a snout-like process, a fact which is of interest in connexion with the a.s.sertion that in _Balaenoptera_ the blow-hole is puffed out during spouting. What is temporary in the Rorqual appears to be permanent in the _Sotalia_. More remarkable still, perhaps, is the a.s.sertion that it is a vegetable-feeding Dolphin. This is not a mere a.s.sertion except that it may not apply universally; for in the stomach of a specimen nothing but vegetable debris was found. But in the stomachs of other Whales (e.g. _Rhachianectes_) vegetable matter has also been found, which may perhaps have been taken in accidentally with the food.