MISCELLANEOUS EXAMPLES.
In this chapter a few of the rarer examples of hair-clad mammals which
present remarkable changes at critical areas of their hairy coats
may be considered with advantage. I have chosen six, of which three
appeared in my former book.
The Giraffe.
The two drawings of a giraffe, Figs. 43 and 44 were made for me for the
purpose of illustrating one of its habits and two of its peculiarities
of arrangement of its hair. This stately creature is the tallest known
animal and is the sole representative of its ancient family, more
common in the days when giants abounded. Its range is becoming more
limited and its enemies not less dangerous, and it is expected in the
course of some years to add to the number of the recently-extinct
creatures.
Habits.
Living mainly in dry sandy regions giraffes find their food exclusively
in leaves plucked from trees, and are said by some authorities to exist
for a long period without drinking, but an interesting account quoted
by Lydekker from Selous should be mentioned here. Selous writes that
on a certain occasion he reached camp “a little before sundown, just
in time to see three tall, graceful giraffes issue from the forest a
little distance beyond, and stalk across the intervening flat, swishing
their long tails to and fro, on their way down to the water. It is a
curious sight to watch these long-legged animals drinking, and one that
I have had several opportunities of enjoying. Though their necks are
long, they are not sufficiently so to enable them to reach the water
without straddling their legs wide apart. In doing this, they sometimes
place one foot in front, and the other as far back as possible, and
then by a series of little jerks widen the distance between the two,
until they succeed in getting their mouths down to the water; sometimes
they sprawl their legs out sideways in a similar manner.” Lydekker
adds that this position has to be assumed not only when drinking,
but likewise when the animal desires to pick up a leaf from the ground
or on the rare occasions when it grazes. This habit so graphically
described is the one which alone concerns my subject. The patterns of
hair peculiar to the giraffe need a short description.
[Illustration: Fig. 43.--Giraffe showing at A and B, hair-patterns of
a remarkable kind at the place where the main movements of the neck
occur.]
[Illustration: Fig. 44.--Giraffe in the act of drinking or browsing off
the ground.]
Hair Patterns.
Fig. 43 shows a whorl (B) at the side of the neck on a level with the
prominent spines of the seventh cervical and first dorsal vertebræ. It
lies exactly over a spot which may be well called a “critical area,”
for an important hinge of the whole mechanism of the giraffe’s great
neck is situated here. Though the remarkable length of its neck is
intimately associated with its daily needs for protection against
enemies and the supply of food from high-placed branches of trees, it
forms a real obstacle to the less important need of obtaining water
to drink or food from the ground as Selous and Lydekker show. The
protective value of the neck is picturesquely described by Mr. Beddard
when he speaks of it as the giraffe’s watch-tower, whence its keen
eyesight surveys the surrounding country for its enemies. But its
attitude in drinking, Fig. 44, gives a vivid idea of the play of forces
which takes place at the great hinge between the neck and the trunk,
and at this point the whorl has been produced on the skin in the course
of its laborious efforts to supply itself with water. The absence of
any other whorl or reversed hair on the whole of its neck and trunk is
most significant from the point of view of the dynamics of hair.
The second departure from the normal direction of hair is found on
the prominent portion of the spine, and it lies over this hinge-area.
In Fig. 44 is shown the mane proceeding along the whole of the neck
in the normal downward direction, and the arrows indicate the way in
which it becomes suddenly reversed at the critical point and the lowest
portion of the mane stands up and points upwards. This change is shown
by the two arrows whose points meet one another, and the facts of its
occurrence, here and nowhere else, at once suggest that the habit which
produced the whorl on the side of the neck has also contributed to the
change in the direction of the mane. The pattern here is precisely of
the same order as that of the cow’s neck which we saw to be caused by
its habit of browsing off the ground.
Bongo--Tragelaphus euryceros.
This West African antelope is a forest-dwelling species, about which
little is known as to its habit of life, though its form and anatomy
are well described by Lydekker. It has a powerful chest, long and
strong horns, and short hoofs, and it is shown in Fig. 45 with its
large pectoral whorl, feathering and crest, in which it strongly
resembles the domestic horse. One may be allowed here, as exact
knowledge is wanting, to point out that “reconstruction” of its habits
may be reasonably attempted along the lines laid down in these pages.
It is doubtful if any large mammal could possess so powerful a fore-end
with very muscular forelimbs, highly-developed pectoral patterns and
short strong hoofs without being a very fleet animal much accustomed to
relying upon its speed for its protection, and if a greater knowledge
of it be obtained in the future it is highly probable that this
prediction will be verified. Part of its habitat is described as the
Ashkankolu Mountains, a region where speed would be of great value.
[Illustration: Fig. 45.--Bongo. Showing on the strong muscular chest,
well-formed pectoral patterns.]
Kiang--Thibetan Wild Ass.
This member of the Equidæ is shown in Fig. 46 and there is an excellent
specimen of it at South Kensington. I have chosen it because it is very
unusual among others of its family in the possession of an inguinal
and axillary whorl, feathering and crest. No other than the domestic
horse that I have examined shows these patterns. They are nearly as
well developed as in the horse, and require no special description. It
lives in high altitudes up to fourteen thousand feet, and travels often
in large herds, its food being composed of the various woody plants
of these dry and barren regions. Lydekker says that it “is remarkable
for its fleetness and its capacity for getting over rough and stony
ground at a great pace.” From these facts one can gather that a large
portion of its working day would be spent in rapid locomotion from
place to place in search of its sparse food-supplies and in avoiding
enemies--two paramount objects of its existence which are pictured in
the two animal pedometers displayed on its hairy coat.
[Illustration: Fig. 46.--Kiang. Side view showing inguinal (W F C) and
axillary (W F C) patterns.]
Llama--L.
I refer here to the true llama or domesticated form of the genus Llama,
of which the vicunha and huanaco are the existing wild species. In the
stirring time when a handful of Spanish Conquistadores under Pizarro
conquered and trampled upon the ancient civilisation of the Incas this
useful animal was employed to an immense extent as a beast of burden.
Lydekker says that at the time of the Conquest of Peru it was estimated
that three hundred thousand llamas were employed in the mines of
Potosi alone. Prescott gives an excellent account of the use of this
animal in his _Conquest of Peru_. They were valued highly for their
strength and sureness of foot which were much needed in their long and
rugged journeys over the great passes of the Cordilleras, as well as
for the excellence of their flesh.
[Illustration: Fig. 47.--Fore foot of llama shown from behind (A) and
from side (B) with whorls of hair and reversed areas on each side.]
The only region of a llama’s body which is of interest in the present
inquiry is the fore-foot, figured in Fig. 47. It presents a very
remarkable arrangement of hair on its under surface, just above the
double hoof and spongy pad at the joint above the hoof. This is
found on each side towards the outer border of the hollow region,
and consists of a whorl from which the hairs radiate in a reversed
direction towards the upper part and transversely across the rest
of the hollow. Prescott speaks of “its spongy hoof, armed with a
claw or pointed talon to enable it to secure hold on the ice,” and
adds that “it never requires to be shod.” If one reflects upon the
ceaseless action during rough and slippery locomotion of this animal
throughout its working life on mountain passes, on rough stony paths
and ice-covered places, one can have no doubt of the reason why this
particular joint, so greatly used in maintaining a foothold, should
have acquired on this sheltered portion of its hair an animal pedometer.
The Parti-coloured Bear--Æluropus Melanoleucus.
This is a rare and peculiar form of the family of Ursidæ about which I
made a statement some years ago at the Zoological Society of London.
It is a “stocky” animal with a small head and broad short muzzle, a
feature to which it has no right according to its affinities. It is not
a member of the high-class Felidæ whose special prerogative it is to
wear their hair on a short broad muzzle in a _downward_ direction as
I showed in Chapter XI. Being a more _bourgeois_ creature than a cat
it has offended against such sumptuary laws as may exist in the animal
kingdom.
Its hair ought to be worn in the proper backward or upward slope such
as other bears, dogs and small carnivores display.
In my former note I modestly proposed an alternative suggestion to the
one I now offer, of this aberrant and strange bit of hair-country,
and this was that it was correlated with the broad short snout. As I
have remarked before this word “correlated” is used so loosely as to
mean almost anything the user likes, and it is, in my opinion, a fine
source of confusion of thought. Undoubtedly this shape of the muzzle
of the Parti-coloured Bear is linked somehow with the arrangement
of its hair on that region. But it is hardly to be imagined that
a direct reversal of hair from the proper bear-type, that is to say
from the mouth to the head, would be produced by the mere broadening
of the muzzle on account of some adaptation to its altering life. The
link surely is of a different nature, and analogous to that of the
corresponding surface in the lion and other cats, and that the cleaning
of its fur on the snout is done in feline and not in ursine fashion,
that is to say forwards, and that the breadth of muzzle is the reason
for the change of method.
Two-Toed Sloth--Cholæpus didactylus.
This weird creature is one of a decaying family whom naturalists, with
needless and frank brutality, called toothless. The term is neither
exact nor polite. It is very much as if one were to call a person
“toothless” whose front teeth had been knocked out, but whose remaining
teeth were good and useful. But it represents so important a taxonomic
character that one must allow for what seems bad manners on the part
of zoological leaders who are, as a rule, full of the milk of human
kindness, and seldom in these days quarrel even among themselves,
adopting the motto _nihil animalium alienum a me puto_.
[Illustration: Fig. 48.--Two-toed sloth, showing action of gravity upon
the long thick hairs.]
The sloths form an excellent example of the action of gravity upon long
thick hairs, and the Fig. 48 given will explain this. They are New
World animals, though indeed they have what we call an “Old World”
look, and are truly ancient. They spend the larger part of their
time upside down in the manner represented in the drawings. They are
arboreal and nocturnal animals that come down to earth in search of
food when things are quieter below, and will wander for considerable
distances, walking slowly on the outer borders of their feet and the
feet turned in.
These being the few facts of their lives which concern the present
subject one comes, as usual, to interpretation. These tree-sloths are
descended from an older form that inhabited the ground, so that the
present mode of life, which is so largely arboreal, has been acquired
by dint of long years of struggle and adaptation to bitter needs.
It seems hardly reasonable to call in the aid of selection for the
production of its singular disposition of hair though that factor ruled
in the production of its arboreal habit. It is almost flying in the
face of common sense to attribute this upward, or downward (according
to one’s point of view) singular arrangement to anything but the
effects of gravity upon its long hairs. If it be not so, it looks a
remarkable likely solution of this small problem.