WORK ON THE CETACEA
Next at any rate to the study of the various races of the human species
(which he took up seriously later on in his career), the group of
mammals to which Flower devoted special attention, and which attracted
his greatest interest, was undoubtedly that of the Cetacea, or whales,
dolphins, porpoises, etc. At the time when he set himself seriously to
study these aquatic and fish-like mammals, the zoology of the group was
certainly in a most confused and unsatisfactory state; partly, no doubt,
owing to the comparative rarity of complete specimens in our museums, and
the consequent difficulty of instituting accurate comparisons, and partly
to the reckless prodigality with which names had been given to imperfect
or insufficiently characterised specimens by some of his predecessors and
early contemporaries, and the needless multiplication of generic terms.
It was consequently at this time almost impossible to be sure which was
the right name for even many of the commoner species; while in the case
of the rarer kinds, the confusion was almost hopeless. When Flower left
the subject—which he only did when his working days were over—it was in
great measure thoroughly in order, although of course much was left for
future workers to fill in. Unhappily, his views on the nomenclature of
the group have not been accepted by all his followers; so that a fresh
and totally unnecessary source of confusion has been introduced of late
years into a subject which had already sufficient difficulties of its own.
In regard to the discrimination of species, Flower took a view almost the
reverse of that held by some of his predecessors and colleagues; and, as
he says himself, he may have consequently erred in a direction the very
opposite of theirs. “As species have not generally been recognised as
such,” he wrote in the British Museum _List_ of 1885, “unless presenting
constant distinguishing characters capable of definition, it is probable
that, in the imperfect state of knowledge of many forms, some may have
been grouped together which a fuller acquaintance with all parts of their
structure, external and internal, will show to be distinct.”
Apart from his explaining to popular audiences that whales were mammals
and not fishes, Flower emphasised three points very strongly in regard
to the organisation and physiology of these animals. First of all,
he pointed out that, as a rule, they do not “spout” water from their
“blowholes.” “The ‘spouting,’ or more properly the ‘blowing’ of the
whale,” he wrote, “is nothing more than the ordinary act of expiration,
which, taking place at larger intervals than in land animals, is
performed with a greater amount of emphasis. The moment the animal rises
to the surface it forcibly expels from its lungs the air taken in at the
last inspiration, which is of course highly charged with watery vapour in
consequence of the natural respiratory changes. This, rapidly condensing
in the cold atmosphere in which the phenomena is generally observed,
forms a column of steam or spray, which has been erroneously taken for
water.”
Secondly, he drew attention to the importance of the rudiments of
hind-limbs which occur in many whales as affording decisive evidence
of the descent of the group from land mammals. And thirdly, he
emphasised the marked distinction between baleen, or whalebone, whales
(Mystacoceti), and toothed whales and dolphins (Odontoceti); although
he appears never to have gone so far in this direction as some modern
naturalists, who are of opinion that these two groups have originated
independently of one another from separate types of land mammals.
Another point to which Flower devoted a considerable share of attention
was the dimensions attained by the larger species of whales. Previously,
there is no doubt that very great exaggeration had been current in this
respect, and that such things as 150-feet whales are unknown. With his
excessive caution, and determination to be on the safe side, it is
however probable that in some instances—notably the Greenland right-whale
and the sperm-whale—Flower somewhat under-estimated the maximum
dimensions.
At what date Flower first began to study whales seriously, it is not
easy to ascertain. From the fact of his contributing three papers on
this subject to the Zoological Society’s _Proceedings_ for 1864, it may,
however, be inferred that by that time he had devoted no inconsiderable
amount of attention to the group. In the first of those he described a
specimen of a lesser fin-whale, then recently stranded on the Norfolk
coast; while in a second, and much more important communication, he gave
notes on the skeletons of whales preserved in the museums of Holland
and Belgium which he had recently visited. Two of these he described as
indicating apparently new species; although their right to distinction
was not maintained. In the same year he described two skulls of grampuses
from Tasmania, which were regarded as representing a new species, under
the name of _Orca meridionalis_; a further note on these being added in
the Society’s _Proceedings_ for 1865, when the species was transferred
to the genus _Pseudorca_. Later still it was found that the supposed
species was inseparable from the typical _P. crassidens_; named by Owen
many years previously on the evidence of a skeleton from the Lincolnshire
Fens. In another note published the same year in the same journal he
showed that one of the whales named by him in 1864 was identical with the
one now known as _Balænoptera sibbaldi_; while a second paper described a
specimen of the fin-whale commonly known as _B. musculus_. A further note
on the synonymy of _B. sibbaldi_ appeared in the _Proceedings_ for 1868.
Reverting to earlier publications, in 1866 the Royal Society of
London issued a volume containing translations by Flower of certain
very important memoirs on Cetacea by Professors Eschricht, Reinhardt,
and Lilljeborg. As these were written in a language understood by
comparatively few Englishmen, the translation was a distinct benefit to
“cetology” in this country.
Between the years 1869 and 1878 inclusive, six very important memoirs on
whales (including in that term porpoises, dolphins, etc.) from Flower’s
pen appeared in the _Transactions_ of the Zoological Society of London.
The first of these, which was published in the year first mentioned, was
devoted to the description of the skeleton of the very interesting and
then little-known South American freshwater or estuarine dolphins, _Inia_
and _Pontoporia_. In the course of this memoir it was demonstrated that,
in spite of the wide distance between their habitats, these dolphins and
the freshwater dolphin of the Ganges and certain other Indian rivers,
_Platanista gangetica_, collectively form a distinct family group—the
Platanistidæ, which exhibits many very generalised features.
In the second memoir of this series, which appeared in 1869, Flower
treated in an exhaustive manner of the osteology of the sperm-whale, or
cachalot. “The fine skeleton of a young male which he procured for the
Museum of the Royal College of Surgeons,” writes Professor M’Intosh in
his obituary notice of Sir William, “formed the basis of this important
paper, and enabled him to add to and correct much which had been written
on this subject. The description of its huge cranium as a large, pointed
slipper, with a high heel-piece and the front trodden down, the hollow
limited behind by the occipital crest, continued laterally into the
elevated ridges of the broadly expanded maxillæ, which rose from the
median line to the edge of the skull, instead of falling away, as in most
Cetaceans, must be familiar to all students of the group. In this vast
cavity lies the ‘head-matter,’ composed of almost pure spermaceti.”
It was further demonstrated that the available evidence pointed to the
existence of only a single species of true cachalot; the small adult jaws
not unfrequently seen in collections being apparently those of females,
which are known to be far inferior in size to the old bulls.
It may be added, in connection with sperm-whales, that the abrupt
termination of the muzzle, shown (in a somewhat modified degree) in the
model of the old bull, set up under Sir William’s direction in the Whale
Room at the Natural History Museum, has been said by certain modern
naturalists to be incorrect. Inquiries instituted at the present writer’s
suggestion at the New Bedford Cachalot-whaling Station have, however,
proved that the abruptness is under-estimated rather than exaggerated in
the restoration.
This brief reference to the Whale Room at the museum, and Flower’s work
in superintending the construction of models of several of the larger
members of the group, must, it may be further added, suffice in this
place, seeing that fuller mention of the subject has been already made in
an earlier chapter.
The third memoir of the series in the Zoological Society’s _Transactions_
treats of the Chinese white dolphin (_Delphinus_, or _Prodelphinus_,
_sinensis_), and was published in 1872. In the following year appeared
one on Risso’s dolphin, _Grampus griseus_, in which the author directed
attention to certain variable markings always seen on the skin of this
species. These, it has been subsequently shown, are produced by the claws
in the suckers of the cuttlefish which forms the food of this species.
The two remaining memoirs in the _Transactions_, which appeared
respectively in 1873 and 1878, were devoted to that difficult, and at
the time imperfectly known group, termed ziphioid, or beaked whales. In
the first of the two attention was concentrated on the aberrant and
rare form known as _Berardius arnuxi_; while the second was exclusively
devoted to the much more abundant types included under the generic title
_Mesoplodon_, in allusion to the single pair of lower teeth near the
middle of the sides of the lower jaw, which forms the single dental
armature of the cetaceans of this genus. The beaked whales, it should be
added, had been previously discussed by Flower in a preliminary paper
published in the Zoological Society’s _Proceedings_ for 1871 and 1876,
and likewise in an article communicated in 1872 to _Nature_.
Special interest attaches to a paper by Flower published in the
_Transactions_ of the Royal Geological Society of Cornwall for 1872,
and also in the _Annals and Magazine of Natural History_ for the same
year, on the bones of a whale dug up at Petuan, in Cornwall, sometime
previously to 1829, and now preserved in the museum of the above-named
Society. The whale represented by these remains was made the type of the
new genus and species _Eschrichtius robustus_, by the late Dr. J. E.
Gray. That it was a member of the group of whalebone-whales, and that
it could not be identified with either of the genera then known, namely
_Balæna_, _Balænoptera_, and _Megaptera_, was fully demonstrated by
Flower, who also showed that it agreed with the two latter in having the
neck-vertebræ free.
“The interesting question,” he added, “remains, whether this species
still exists in our seas; if extinct, it must have become so at a
comparatively recent period, certainly long after Cornwall was inhabited
by man. The negative evidence of no specimen having been met with by
naturalists in a living or recent state, is hardly conclusive as to its
non-existence, as our knowledge of this group of animals is lamentably
deficient. We are acquainted with many species, even of very large size,
only through isolated individuals, and the discovery of others new to
science is by no means an infrequent or unlooked-for occurrence at the
present time.”
In the opinion of the present writer, it is quite probable that this
whale may be identical with the grey whale of the Pacific, described many
years subsequently by the late Professor Cope as _Rhachianectes glaucus_,
in which event that name will have to give place to _Eschrichtius
robustus_.
In the year 1879, and for some time after, Flower directed his attention
more especially to the dolphins and porpoises, which collectively
constitute the family Delphinidæ of naturalists, and he published a
series of papers on this group in the _Proceedings_ of the Zoological
Society. In the volume for 1879 there appeared, for instance, one paper
on the common dolphin (_Delphinus delphis_); a second on the bottle-nosed
dolphin, now known as _Tursiops tursio_; and a third on the skull of
the white whale, or beluga (_Delphinapterus leucas_). Of far greater
importance was, however, the appearance in 1883 of a paper in the same
serial on the generic characters of the family Delphinidæ as a whole.
Special attention was directed in this communication to the value of the
pterygoid bones, on the under surface of the skull, in the classification
of the family; and characters were formulated which enabled the various
genera to be identified, wholly or in part, by this part of the skull.
Flower’s classification of the Delphinidæ has, with some slight
modifications, been very generally accepted by later naturalists. Some
time after the publication of this paper the present writer pointed
out to the author that two of the generic names employed by him were
barred by previous use in a different sense; and in a note subsequently
published in the _Proceedings_, these were accordingly replaced.
Flower was, however, by no means forgetful of his earlier love for the
cachalot and beaked whales (Physeteridæ); and in 1883 and again in 1884
he published papers in the _Proceedings_ on their near relatives the
bottle-nosed whales (not to be confounded with the bottle-nosed dolphins)
of the genus _Hyperöodon_. In these investigations he was much indebted,
as on several previous occasions, to the observations of Captain Gray, a
well-known whaler. As regards the common bottle-nose (_H. rostratus_),
Sir William succeeded in demonstrating that the great differences which
had long been noticed in the skull were due to distinctions either
of sex or age; the old males developing huge maxillary crests—with a
broad and flattened front surface—of which there is scarcely any trace
in the younger members of the same sex, or in females of all ages. In
consequence of this difference in the skull, the head of the old bull
bottle-nose is easily recognisable by the abrupt and prominent elevation
of the forehead immediately behind the base of the beak. Flower was
also able to show that bottle-noses yield true spermaceti, especially
in the head; a fact which does not appear to have been previously known
to zoologists, although it may have been to whalers. At the present day
there is a considerable trade in bottle-nose sperm-oil and spermaceti;
these being often blended with the products of the cachalot, from which
they are distinguishable by their specific gravity. In his 1882 paper
Flower described a water-worn bottle-nose skull from Australia, which
he regarded as indicating a second species of the genus—_Hyperöodon
planifrons_. The correctness of this determination has been demonstrated
by complete skeletons of the same whale from the South American seas.
The last two papers on Cetacea by Sir William in the _Proceedings_ of
the Zoological Society refer to the occurrence of examples of Rudolphi’s
rorqual (_Balænoptera borealis_) on the English coasts. In the one paper
he described a specimen stranded on the Essex shore in 1883, and in the
other an example captured in the Thames four years later.
As regards other contributions to our knowledge of the Cetacea, Sir
William in 1883 delivered before the Royal Institution a lecture on
“Whales, Past and Present,” which is reproduced in the _Proceedings_ of
that body for the same year. A second lecture, “On Whales and Whaling,”
was delivered before the Royal Colonial Institute for 1885, and is
published in the _Journal_ of the Institute for that year. The article
“Whale,” for the ninth edition of the _Encyclopædia Britannica_, is also
the work of Flower; it is reproduced, almost as it stands, in the _Study
of Mammals_.
The year 1885 saw the publication of the “List of the Specimens of
Cetacea in the Zoological Department of the British Museum,” a small, but
nevertheless valuable work, from which an extract has already been made.
Even when this was written, the museum contained skulls or skeletons of
nearly all the more important and well-established representatives of the
order, the only notable deficiency being the large whalebone whale from
the North Pacific commonly known as the grey whale, and scientifically
termed _Rhachianectes glaucus_. It was not many years before this gap
was filled by the acquisition of a complete skeleton of the species in
question.
In concluding this brief notice of the work accomplished by Flower on the
Cetacea, an extract may be made to illustrate his views with regard to
the ancestry and origin of the group:—
“The origin of the Cetacea,” he wrote, “is at present involved in much
obscurity. They present no signs of closer affinity to any of the
lower classes of vertebrates than do many other members of their own
class. Indeed in all that essentially distinguishes a mammal from the
oviparous vertebrates, whether in the osseous, nervous, reproductive, or
any other system, they are as truly mammalian as any other group. Any
supposed marks of inferiority, as absence of limb-structure, of hairy
covering, of lachrymal apparatus, etc., are obviously modifications (or
degradations, as they may be termed) in adaptation to their special mode
of life. The characters of the teeth of _Zeuglodon_ and other extinct
forms, and also of the fœtal Mystacocetes, clearly indicate that they
have been derived from mammals in which the heterodont type of dentition
was fully established. The steps by which a land mammal may have been
modified into a purely aquatic one are indicated by the stages which
still survive among the Carnivora in the Otariidæ and in the true seals.
A further change in the same direction would produce an animal somewhat
resembling a dolphin; and it has been thought that this may have been the
route by which the Cetacean form has been developed. There are, however,
great difficulties in the way of this view. Thus if the hind-limbs had
ever been developed into the very efficient aquatic propelling organs
they present in the seals, it is not easy to imagine how they could
have become completely atrophied and their function transferred to the
tail. So that, from this point of view, it is more likely that whales
were derived from animals with long tails, which were used in swimming,
eventually with such effect that the hind-limbs became no longer
necessary. The powerful tail, with its lateral cutaneous flanges, of an
American species of otter (_Lutra brasiliensis_) may give an idea of
this member in the primitive Cetaceans. But the structure of the Cetacea
is, in so many essential characters, so unlike that of the Carnivora,
that the probabilities are against these orders being nearly related.
Even in the skull of the _Zeuglodon_, which has been cited as presenting
a great resemblance to that of a seal, quite as many likenesses may be
traced to one of the primitive Pig-like Ungulates (except in the purely
adaptive character of the form of the teeth) while the elongated larynx,
complex stomach, simple liver, reproductive organs, both male and female,
and fœtal membranes of the existing Cetacea, are far more like those of
that group than of the Carnivora. Indeed, it appears probable that the
old popular idea which affixed the name of ‘Sea-Hog’ to the porpoise,
contains a larger element of truth than the speculations of many
accomplished zoologists of modern times. The fact that _Platanista_,
which, as mentioned above, appears to retain more of the primitive
characteristics of the group than any other existing form, and also the
distantly related _Inia_ from South America, are both at the present day
exclusively fluviatile, may point to the freshwater origin of the whole
group, in which case their otherwise rather inexplicable absence from the
seas of the Cretaceous period would be accounted for.
“On the other hand, it should be observed that the teeth of the
Zeuglodonts approximate more to a carnivorous than to an ungulate type.”
This difficulty with regard to the teeth is indeed one which it is
impossible to disregard, since it is scarcely credible that grinding
teeth such as characterise herbivorous mammals of all descriptions
could ever have been modified into the teeth of whales, either living
or extinct. There is, moreover, the unmistakable resemblance presented
by the cheek-teeth of the aforesaid extinct zeuglodons to those of
Carnivora. Both these facts seem to point to the derivation of toothed
whales, at any rate, from flesh-eating rather than herbivorous mammals;
although they have certainly no relationship with the eared seals.
Since the foregoing passage was written it has been practically
demonstrated that the toothed whales, at any rate, are the descendants
of primitive Carnivora. Professor E. Fraas, of Stuttgart, and Dr. C.
W. Andrews, of the British Museum, have, for instance, shown that the
zeuglodons are derived from the Eocene group of Carnivora known as
Creodontia; while there is every reason for regarding the zeuglodons
themselves as the ancestors of modern toothed whales.