One or two dark- contoured nerve tubules come
up through the base of the papilla, and running
along one side of the corpuscles, thin out and
terminate, without, so far as I have been
able to see, entering its substance. In fact,
these nerve tubules are, as Kolliker pointed
out, accompanied by a delicate neurilemma,
and the axile corpuscle itself appears to me
to be nothing more than the enlarged end
of this neurilemma.
In Birds, a large proportion of the tegumen-
tary nerves terminate in bodies which are, on
the one hand, related to these axile corpuscles,
and on the other to the well-known Pacinian
bodies (fig. 322). They are, in fact, usually
described under the latter name; but their small
size and superficial position, the paucity of their
concentric lamellae, and the transverse striation
of the solid central axis, ally them closely with
the corpuscula tactus. They are found in the
skin around the sacs of the feathers, in the
beak, and in the interosseus spaces of the fore-
arm and leg.
A special article (PACINIAN BODIES) has
already been devoted to the organs of this
kind which are met with in Mammalia, and
it need only be added here, that late re-
searches have shown that the Pacinian bo-
dies of mammals, like those of birds, are
solid masses of rudimentary connective tissue;
the appearance of capsules and of a central
cavity, arising merely from the arrangement of
the elastic element and the extreme transpa-
rency of the collagenous substance. * They are
in fact nothing but thickened portions of the
neurilemma, and the nerve which they enclose
either passes through them, or more usually
* This fact was ascertained and stated indepen-
terminates, more or less abruptly, in the cen-
tral solid axis.
In the article on the PACINIAN BODIES re-
ference is made to the peculiar organs de-
cribed by Savi in the Torpedines. These
Savian bodies, in fact, are little more than
Pacinian bodies converted into sacs by the
development of a cavity between their cen-
tral and peripheral portions. Now Leydi"
has discovered that these feavian bodies do
not stand alone, but that they form a part of
a great series of peculiar integumentary sen-
sory organs, which are most characteristically,
if not solely, developed in the class of Fishes
the so-called mucous canals and follicles.
It has long been noticed, in fact, that in
osseous fishes one series of the scales along
the sides of the body differ in their structure
from the rest, giving rise to what is called the
lateral line; and that a canal runs beneath
these scales from the tail to the head on each
side ; that then becoming connected with its
fellow by a transverse branch over the oc-
ciput, each canal passes forward on the
sides of the head, dividing into two principal
branches, one of which following the course of
the suborbital bones terminates at the end of
the snout, while the other passes down on to
the lower jaw. Similar organs, but having a
more complicated arrangement, are known to
exist in the cartilaginous fishes ; but it is com-
monly supposed that these canals and follicles
secrete the mucus with which the skins of
fishes are lubricated. However, in a very beau-
tiful series of researches, Leydig has shown
that the mucus is furnished by the cellular
ecderon, and that the so-called mucous canals
and follicles are sensory organs. The limits
of this article will not permit me to enter
into any of the details of structure of these
organs, but they may all be described generally
as sacs or canals lined by a cellular investment
like that of the skin upon which they open,'
and filled with a more or less gelatinous sub-
stance. If the organ be a sac, a single pro-
tuberant knob, if a canal, a series of them pro-
ject into the cavity. Each knob is covered
by a coat consisting of tiers of much-elongated
cylindrical cells. Its substance consists of
niore or less gelatinous connective tissue, and
it receives a nerve (a branch of the fifth or of
the vagus), whose fibres divide and become lost
in its tissue. In the osseous fishes this nerve
usually perforates the peculiarly modified scale
of the lateral line, which supports and encloses
the canal at these points. In the cartilaginous
nsnes, the canals have sometimes special fibro-
cartilaginous coats; or if sacculi, a number of
them may be contained in a common cartila-
ginous investment, as in the Chima?ra. Leydi"
insists with great justice on the identitv of
the structure of these organs with that of the
semicircular canals of the ear.
The connection of these sacs and canals with
the corpuscula tactus and Pacinian bodies
dently and contemporaneously in 1853, by Leydur
and myself. See Quarterly Journal of Mk?
Science No. V., and Siebold and Kolliker's Zeit-
schnft, B. v. Heft 1.
TEGUMENT ARY ORGANS.
505
appears to me to be clear ; for the knob which
projects into the cavity of the mucous canal
is homologous with the central " nucleus " of
the Savian body, and this with the solid axis
of the Pacinian body,and with the corpusculum
tactus, so that the " tactile " sac of the Chi-
maera, e. g., may be said to be a tactile cor-
puscle which is connected with the surface of
the integument.
No organ at all resembling these has cer-
tainly been met with, above the class of Fishes,
in either Reptilia or Birds, but in Mamma-
lia there are structures which must, I think,
be placed in the same category. About the
lips and nose of almost all mammals in fact,
there are certain long, strong hairs, the vi-
brissae or "whiskers" (fig. 321.). These in
their general structure resemble ordinary hairs,
but the sac of each, instead of lying free in
the enderon, is enclosed in a second thick sac,
composed of firm, dense, connective tissue,
which attains at times an almost cartilaginous
hardness. A looser areolated tissue connects
this with the outer surface of the proper hair
sac, and supports an abundant .vascular net-
work proceeding from vessels which enter at
the deep end of the sac. Furthermore, a very
considerable nerve pierces one side of the
" sclerotic " coat near this end, and passes to
the surface of the proper hair sac, upon which
it spreads out and forms a nervous expansion,
its fibrils dividing and subdividing, and so
terminating.
Fig. 321.
mammal and the fish, I think one cannot but
be struck with the similarity of plan between
their vibriss3 and the " tactile " canals. The
sensory impression is conveyed to the gelati-
nous contents of the canals in the fish by the
vibration of the dense medium in which it
lives; while in the mammal the impulse is
communicated by the contact of some external
object with a long elastic hair lever; but the
final arrangement for the receipt and appre-
ciation of the impressions is essentially the
same in each case, nor indeed does it differ
from that which is met with in the highest
organs of sense.
Muscles of the enderon. In the Invertebrata
the great majority of the muscles are, as is
well known, inserted into the integument, but
those which are attached to the chromato-
phora of mollusks and to the spines of an-
nelids and other worms, might be regarded
as belonging more especially to the integu-
mentary system.
In Fishes and Reptiles the superficial layer
of striped muscles of the body is always more
or less connected with the integument ; but
hitherto no unstriped fibres appear to have
been detected in it. In Birds, however, the
unstriped muscles attain a very great develop-
ment, forming a thick layer whose bundles (c)
run between and are attached to the sacs of
the feathers (Jig. 322.).
Fig. 322.
Vibrissa from the snout of the Mouse,
a, " sclerotic " sac ; 6, hair-sac ; c, nerve-trunk ; d,
muscular fibres.
Considering the different habits of life of the
Pacinian body (6) and feather-sac (a) from the
base of the mandible of a pigeon, c, muscles of
the feather sacs.
In the majority of Mammals there is a
special teguraentary striped muscle, which
attains an enormous development in the
hedgehog, while a mere rudiment of it remains
in man, as the platysma myoides. Here,
however, the striped "peaucier" muscle is
replaced by the unstriped bundles which, as
Kolliker has shown, run from the upper layer
of the enderon to the bases of the hair sacs,
and effect the various movements of which
the hairs are capable.
506
TEGUMENTARY ORGANS.
Calcareous deposits in the cnderon. Deposits
of this kind are very frequent in the Inverte-
brata. In the Pulmonate and some Gasteropod
Mollusks, for instance, globular masses of car-
bonate of lime are scattered through the en-
deron, and would almost seem to take the place
of fat. In nudibranchiate mollusks, such as the
Dorida3, spicula of like nature are met with,
and these sometimes unite into true internal
shells, as in the genus Villiersia. The greater
part of the skeleton of the Actinoid polypes,
and the whole of that of the Echinoderms, is
composed of calcareous networks of this kind,
and globular masses of calcareous matter are
scattered through theenderori of the Taeniadae,
though the clear spherical bodies observed in
these worms are by no means always of this
nature. Whether these ^nderonic calcareous
deposits ever take place in the Vertebrata ap-
pears to me to be, as I have said above, an
open question, only to be decided by a very
careful examination of the mode of growth
of their so-called "dermal" bones.
BIBLIOGRAPHY. General Works. Heusinger,
Histologie. Quekett, Lectures on Histology.
VERTEBRATA. Gurlt, Untersuchungen ttber die
hornigen Gebilde d. Menschen u. d. Haus-sauge-
thiere (Mliller s Archiv., 1836). Idem, Vergleichende
Untersuchungen tiber die Haut der Menschen und
d. Haus Saugethiere (Muller's Archiv., 1835).
Meyer, Haut d. Cetaceen. Meyer, Baa d. Haut
des Gurtelthieres (Muller's Archiv., 1848.) Eble,
Lehre von d. Haaren, (Consult also for the Hairs,
&c. the works cited in Henle's Allgemeine An-
atomie, and Kolliker's Mikroscopische Anatomic.)
Feathers : Dutrochet, Observations sur la Structure
et la Regeneration des Plumes (Journal de Physique,
Ixxxviii.). F. Cuvier, Observations sur la Structure
et Developpeinent des Plumes (Mem. du Museum,
xiii.). Michel, (in Reil's Archiv., xiii.). South,
Art. Zoology ( Encyclopaedia Metropolitana.) Scales
and integumentary organs of fishes. Leeuwenhoeck,
Arcana Naturae. Reaumur (Mem. de 1'Acad. Roy.
des Sciences, 1716). Mandl, Sur les Ecailles des
Poissons (Annales des Sciences Naturelles, 1839.).
Agassiz, Observations sur la Structure et le Mode
d'Accroissement des Ecailles des Poissons (Annales
des Sciences Naturelles, 1840 ; and Poissons fos-
siles, Vol. I.). Williamson, On the Microscopic
Structure of the Scales and Dermal Teeth of some
Ganoid and Placoid Fish (Phil. Trans. 1849).
Williamson, On the Structure and Development of
the Scales and Bones of Fishes (Phil. Trans. 1851).
Leydig, Histologische Bemerkungen ttber den Polyp-
terus bichir (Siebold und Kolliker's Zeitschrift,
1853). Leydig, Beitrage zur Mikroskopischen An-
atomic und Entwickelungs Gesehichte der Rochen
u. Haie, 1852. Leydig, Haut der Sttss-wasser Fische
(Siebold u. Kolliker's Zeitschrift, 1851). Leydig,
Schleim-kanale d. Knochenfische (Muller's Archiv.,
1850). Peters, Report on the Memoirs of Mandl
and Agassiz (Muller's Archiv. p. ccix. 1841). Rathke,
Ueber die Beschaffenheit des Lederhaut bei Am-
phibien und Froschen (Muller's Archiv., 1847).
Czermak, Ueber die Haut Nerven des Frosches
(Muller's Archiv., 1849.)
ANNULOSA. Lavalle, Annales des Sciences
Naturelles. Carpenter, Report on the Microscopic
Structure of Shells (Rep. Brit. Assoc. 184S).
Mayer, Ueber den Bau d. Hornschale der Kafer
(Muller's Archiv., 1842). Newport, On the Natural
History and Development of the Oil- beetle Meloe
(Linnaian Transactions, 1845-7). Leydig, Ueber
Argulus foliaceus (Siebold und Kolliker, Zeitsch,
B. II.). Leydig, Zur Anatomic von Piscicola geo-
metrica (Zeitsch. I.). Let/dig, Ueber Artemia salina
und Branchipus stagnalis (Zeitsch. III.) Hollard,
Recherches sur les Oaracteres anatomiques des De-
pendances de la Peau chez les Animaux Articules
(Revue et Mag. de Zoologie, 1851). Meissner,
Beitrage zur Anatomic und Physiologic von Mermis
albicans (Siebold und Kolliker's Zeitschrift, 1853).
Quatrefages, numerous Memoirs in the Annales des
Sciences.
MOLLUSCA. Poll, Testacea utriusque Sicilian,
1791. Gray, Some Observations on the Economy
of Molluscous Animals (Phil. Trans. 1833). Car-
penter, Report, &c. (Reports Brit. Assoc, 1845).
Leydig, Ueber Paludina vivipara (Siebold und Kol-
liker's Zeitschrift, 1850). Leydig, Anatomische
Bemerkungen ueber Carinaria, Firola, und Amphi-
ora (Zeitschrift, 1851).
(T. H. Huxley.}
RUMINANTIA (Lat. ruminare, to chew
the cud), Eng. Ruminants ; Fr. Ruminans ;
Ger. Wiederk'duende T/tiere, a well denned
order of mammalian quadrupeds, presenting
the following essential characters : Upper
jaw in nearly all cases destitute of incisor
teeth, their place being supplied by a callous
pad, while the lower jaw has six incisives ;
canines inconstant ; molars usually six on
each side of both jaws, with flattened crowns
surmounted by two double and irregularly
crescentic folds of enamel. Stomach com-
pound and divided into four cavities, so as
to provide for the ruminating act. Ccecum
large. Placenta generally in the form of
cotyledons. Feet ungulate and bisulcate.
This order forms two natural divisions,
comprising the Hornless ruminants (akera-
tophora, Col. H. Smith) which are few in
number, and the Horned ruminants (kera-
tophora) which are very numerous. The
English naturalist Ray, who was the first to
propose a classification based on philosophical
principle, enumerated only fifteen species.
Pallas subsequently divided the entire family
into six genera, and the Baron Cuvier into
eight or nine; but the number of subdivisions
held to constitute genera by later authorities
has been very greatly extended. To serve
our present purpose we shall retain only
the Linnean and two other genera, which
may be conveniently arranged under the five
following heads or sub-orders :
Camelus -
\Auchenia -
TMoschus -
< Cervus
(Camelopardalis
f Antilope -
| Catoblepas
( Capra
lOvis
Bovis
The Camelidse differ in many important
particulars from the horned ruminants, and
exhibit an approximation to the Pachy-
dermata. The dental formula is peculiar;
thus in the genus Camelus there are,
I. CAMELIDSE
II. CERVID^E
III. ANTILOPID^E -
IV. (EGOSCERIDJE -
V. BOVIDJE -
Linn.
Illiger.
Linn.
Linn.
Linn.
Linn.
Smith.
Linn.
Linn.
Linn.
3 3
1 1
1 1
3 3
and in this respect the Auchenias, or Llamas,
disagree only in the number of molars, which
is usually fourteen. The distinguishing fea-
tures of this family depend principally upon
RUMINANTIA.
507
the beautiful provision of water-cells in the stomach, the absence of horns and the sub-
walls of the paunch or first cavity of the bisulcate feet, which are "callous beneath, and
Fig. 323.
Skeleton of the Camel. (From Pander and D'Alton.)
have the toes distinct at the tip from the or cotyledonoid form of placenta. Professor
sole."* The uterine and foetal membranes Owen has demonstrated another remarkable
are unprovided with the ordinary ruminant character arising out of the non-development
Fig. 324.
Skeleton of the Deer. (From Pander and D'Alton.)
* Ogilby.
508
RUMINANTIA.
of foramina for the passage of the vertebral
arteries through the transverse processes of
the lower six cervical vertebrae. This ana-
tomical arrangement occurs in no other
existing tribe of mammifers, but in an aber-
rant form of fossil pachyderm (Macrau-
chenia), Dr. Owen has detected the same
anomaly, and has thus established an ad-
ditional connecting link between the Pachy-
dermata arid Ruminantia.
In the classification of the Cervidae given
above we have included two genera not
usually considered as forming a part of this
family. One of the principal characters of
the Cervidae proper consists in the presence
of deciduous horns or antlers : the genus
Moschus, however, like the Camelidae, is
hornless; and the genus Camelopardalis is
provided with persistent horns which are at
all times clothed with a hairy integument.
The dental formula of the Cervidae and all
other horned ruminants is usually as fol-
lows,
3~3
1 1
-M
3 3
3 3
32.
The Musk-deer tribe have in addition two
long and conspicuous canines in the upper
jaw, projecting in the males below the mouth,
(fig. 330.). The male Kijang or Muntjak
(Cervus muntjac, Zimmerman) has likewise
two prominent canines in the upper jaw
(a, fig. 331.). In the Giraffe there is a
complicated glandular and pouch-like struc-
ture in the neighbourhood of the ileo-colic
valve.*
The Antelopidae include the greater num-
ber of the Cavicornua or hollow-horned
division of ruminants in which the bony axis
of the horn is solid, persistent, and destitute
of cavities or pores. They have, for the most
part, a slender figure adapted for rapid pro-
gression, and, like the Stags, are further dis-
tinguished by the possession of infraor-
bital glandular sinuses.
Under the term (Egosceridae (CEgosccros,
Pallas) we have brought together the closely
allied genera Capra and Ovis. The Goats
are characterised chiefly by their long horns,
which are directed upward and backward,
are more or less angular in front, rounded
behind, and generally marked by transverse
bars or ridges. The chin is clothed with a
long beard. The Sheep which have no beard
differ mainly in having the horns directed at
first backward, and subsequently bent spirally
forward. Between the toes at the anterior
aspect of the feet is situated a special glan-
dular sebaceous sac ; this structure is also
found in other ruminants, the Rein-deer,
for instance. Neither the Sheep nor Goats
exhibit the lachrymal sinuses so character-
istic of the majority of the Antelopes and
Stags.
Fig. 325.
Skeleton of the Cow. (From Pander and D'Alton.
The Bovidce present few anatomical pecu-
liarities not shared by the preceding genera.
As regards external configuration, however,
they are at once recognised by their bulky
massive size, the broad muzzle, and powerful
limbs (fig. 325.). The horns are directed
laterally, with an inclination upward more or
less curved. In their habits and in the struc-
ture of the skin, some of the species, the
Buffaloes, for example, approach the pachy-
dermatous type.
Osteology. The general form of the skull
in ruminants, when viewed laterally, is that of
an isosceles triangle, the base of which is
represented by the occipital crest and rami
of the jaw, and the apex by the incisive pro-
minence ; but exceptions occur, as for instance,
in the common sheep, where the frontal bones
are so much arched as to produce a somewhat
oval figure, and in the camel, where, owing
to the abrupt termination of the nasal and
sudden depression of the intermaxillary
bones, an obliquely quadrilateral form is the
result (fig. 331). The forehead is usually-
straight and elevated, the orbits are placed
wide apart, and the muzzle, except in Bovidaj,
* See " Viands of Intestine" in this Article.
RUMINANTIA.
509
is attenuated and compressed. Throughout
the whole order there prevails considerable
disparity as respects the cranium and face;
the bones of the latter occupy fully two-
thirds of the entire length of the skull, and
the area of the face on section is nearly
double that of the cranium.
Bones of the cranium. Eight bones enter
into the composition of the adult cranium ;
viz , an occipital, a parietal, two frontal, a
sphenoidal, an ethmoidal, and two temporal ;
and, in addition to these, some species are
provided with two ossa triquetra or inter-
parietals.
Fig. 326
Skull of the Ox viewed from behind. (From a spe-
cimen in Lond. Coll. Surg. Museum.)
The occipital bone (1 !,./% 326.), as in most
of the mammalia, is originally divided into
four, one superior, one inferior, and two
lateral pieces (11', Jig. 326.). These become
early consolidated, and in the calf at the time
of birth they are firmly united together and
to the parietal and interparietal bones lying
immediately in front. The occipital crest is
prominent in the Llamas, and still more fully
developed in the true Camels. In Bovidae the
crest corresponding to the occipital is formed
by the junction of the parietal and frontal
bones, the superior occipital remaining flat.
In ruminants generally, the paramastoid pro-
cesses (/ Jig. 326.) are much elongated, falci-
form, and curved inwards, and between these
and the occipital condyles (i) a very deep
fossa intervenes. In Camelidae, at the angle
formed by the union of the petrous portion
of the temporal with the lateral and superior
occipitals there is a large opening on either
side. In this family the anterior condyloid
foramina are of moderate capacity, but in
Cervidae they are of great size and some-
times four in number, in which case two
remain small. In CEgosceridse and Bovidae
they are also large and occasionally double.
The parietal (9*) is single, and with a few
trifling variations, is articulated to the cranial
bones in the usual manner. The lambdoidal
or parieto-occipital suture lies considerably
in front of the crest, except in Bovidae,
where it lies below, and is separated from
the frontal suture by the intercalated and
narrow wedge-shaped parietal bone. The
(Egosceridae have the parietal in the form of
a flattened band, encircling the cranium and
extending between the orbitar wings of the
sphenoid on either side (b,Jig. 335.). It is
broader in the goats than in the sheep. In
Bovidae the parietal does not extend so far
forward (b. fig. 327.). In the Giraffe the
lateral processes of the parietal are narrowed
Fig. 327.
Skull of the Ox, viewed laterally. (From Spix.)
to a mere point, but the body of the bone
which reaches from between the horns as far
back as the occipital crest has a longitudinal
diameter of fully six inches. The coronal or
fronto-parietal suture in this species and a
few other genera is situated in a line with
the osseous protuberances which support the
horns. It is most frequently placed behind ;
in the Gazelles, however, it appears in front.
The frontal bones (8) are of large size and
great breadth ; this latter feature being more
especially manifest in the Camels, the Sheep,
and certain bovine species. In the Came-
lidae they extend backward between the
anterior divisions of the parietal bone, and in
front they are articulated to the lachrymals
by a transverse suture, which is less extended
in the Llamas than in the true Camels. In
the Llamas and in the genus Moschus a
small part of the frontal is connected to the
superior maxillary. There are several supra-
orbital or frontal foramina (c) with rounded
orifices, which in the Camels are placed near
the middle line and at the centre of the fore-
head. In the Llamas these openings are
placed rather farther back and united by a
longitudinal groove. The frontals are ele-
* The numerals here refer to all the subjoined
figures of crania with the exception of figs. 327.
and 335.
510
RUiMINANTIA.
vated posteriorly in Bovidae (c, fig. 327.)
and prolonged toward the occipital crest, in
the formation of which they apparently con-
tribute, a circumstance giving rise to the
peculiar physiognomy characteristic of the
group. The osseous protuberances support-
ing the horns, of which we shall speak more
particularly when describing the latter in
detail, take their origin in most cases from the
frontal bones. In the Giraffe the slight
eminences analogous to the osseous cores
are partly formed by the parietal bone, the
coronal suture passing directly through the
centre from side to side (Jig. 328.) ; the an-
Fig. 328.
Front view of the skull of a Giraffe. (From a spe-
cimen in Lond. Coll. Surg. Museum.)
terior or central eminence, situated imme-
diately behind the nasals, and in part formed
by them, differs in no respect, save as regards
its position, from the other two, the elevation
in all instances being produced by the expan-
sion of the cranial sinuses beneath. There is
a single large supra-orbital canal, having its
superior outlet midway between the upper
border of the orbit and the central frontal
eminence (Jig. 328.). In Cervidae generally,
the canal opens at the upper surface by a
longitudinal furrow (fig. 329.), but this is more