humerus, closely resembles the transverse connecting fasciculus in the Mole.

The muscle answering to 'levator scapulæ,' b, rises from the paroccipital, as well as from the cervical diapophyses: it expands to be inserted into the fore and upper angle of the scapula

and the fascia covering the 'infraspinatus:' it is a protractor, or forward rotator, of the scapula. The rhomboideus,' a, is the raiser of the blade-bone. Two strong muscles attached to the paroccipital and mastoid, pass, one, e, to the sternum (sternomastoideus), the other to the humeral tuberosity (sterno-humeralis). The latissimus dorsi,'f, is short and slender, coming off by a few digitations from the ribs, and inserted into the humerus and by an extended aponeurosis into the olecranon. The 'supraspinatus' is small: it is covered by the deltoid,' i. The infraspinatus,' c, is a broad and thin sheet of muscle. Behind it is a 'teres major,' k, also of broad and flat form; and a thick and narrow teres minor,' l. The serratus magnus' does not extend forward beyond the ribs of the dorsal vertebræ.

In the Ungulate series the muscular system has been traced out in both Perisso- and Artio-dactyle species, but most completely in the Horse, figs. 11-13. In this sensitive quadruped the dermal muscles are well developed, enabling it to shake the

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whole skin, rattling the harness which may be attached thereto, and to vibrate particular portions on which an insect or other irritant may have alighted. This panniculus carnosus' is thick upon the neck, whence it passes downward, becoming aponeurotic' upon the fore-limb: the sheets upon the sides and fore part of the trunk send a flat tendon to be inserted, with that of the latissimus dorsi, into the humerus: and other fasciculi pass downward over the muscles of the antibrachium, and

terminate in a fascial expansion over the carpo-metacarpal segment. The posterior part of the panniculus spreads over the loins, and, descending, degenerates into an aponeurosis, which forms, in the male, a sheath for the penis: the hinder portion encases the rump and thigh in a strong carneo-aponeurotic covering, which accompanies the fascia lata to the hind leg. On removing the panniculus carnosus, the superficial proper

muscles of the trunk and limbs are exposed, as in the side view, fig. 11.

The spinalis dorsi' repeats closely the characters of that muscle in Man. Its continuation, the 'spinalis cervicis,' is in the Horse of great strength and importance: its origin commences from the second dorsal spine, which origin is continued for about one-third of the way down that spine toward its root: it arises likewise from the third dorsal spine and the ligamentum nucha; from these origins it runs forward to be implanted by strong and distinct tendons into the spines of the anterior cervical vertebræ.

The longissimus dorsi' is situated immediately external to the spinalis, taking its origin from the common mass of muscle that arises beneath the lumbar fascia, as well as from the spinous processes of the loins and sacrum, whence it runs forward to be inserted by a double set of tendons into the transverse processes of the loins and back, and also into the posterior ribs near their angles. Its continuation, the transversalis colli,' consists of very powerful fasciculi, inserted respectively into the diapophysial parts of the last five cervical vertebræ.

The sacro-lumbalis' arises, in conjunction with the latissimus dorsi, from the back of the sacrum, and also by flat tendons from all the ribs, except two or three of the most anterior; and its slips are inserted by as many distinct tendons into the inferior edge of all the ribs, except two or three of the hindmost, and also into the transverse process of the seventh cervical vertebra. The continuation of this muscle, the cervicalis ascendens,' is chiefly remarkable for the strength of its tendinous insertions into the middle vertebræ of the neck.

The multifidus spinæ,' in the dorsal region, arises by numerous tendons from the metapophyses of the sacral, lumbar, and dorsal vertebræ ; each slip running forward to be inserted into the neural spine of the vertebra in front of that from which it derives its origin, the whole forming a thick mass, which fills up the hollow situated between the spinous and transverse processes. In the neck a similar disposition exists.

Besides the intertransversarii colli,' there is a series of muscles arising from the prezygapophyses of the first dorsal and five last cervical vertebræ, and inserted, severally, into the side of the centrum in advance: they are called by Stubbs 'intervertebrales.”1

The longus colli' arises from the transverse processes of the third, fourth, fifth, and sixth vertebræ of the neck, from which origins it runs upward to be inserted by distinct tendons into the

anterior part of the bodies and transverse processes of the vertebræ above them, and into the anterior surface of the atlas.

The muscles which raise or straighten the tail are the following:

The sacro-coccygeus superior' arises from the third and succeeding sacral spines, and from those of the anterior caudal vertebræ. The fleshy mass formed from these origins gives off numerous slender tendons: the first of these is the shortest, and runs inward to be inserted into the base of the first caudal vertebra, in which the articular apophyses are wanting. The second tendon is inserted in a similar manner into the succeeding vertebra; the third into the next, and so on to the end of the tail. Each tendon is lodged in a sort of ligamentous canal, which forms a sheath for it throughout its whole course. When these two muscles act in concert the tail is raised.

The interspinales superiores' form a continuation of the interspinous series of vertebral muscles; but as the spinous processes of the tail are short, and soon replaced by tubercular rudiments of the neurapophyses, these muscles are here disposed obliquely, being more widely separated posteriorly than they are in front.

The muscles which depress the tail all take their origin in the interior of the pelvis, and are prolonged to a greater or less extent along the inferior aspect of the tail. They form four pairs of series of muscles, called the 'ileo-coccygei,' and 'sacro-coccygei inferiores; the latter are the more direct antagonists of the sacrococcygei superiores, and their tendons are received into sheaths resembling those upon the upper surface of the tail, and are inserted successively into the base of each caudal vertebra, beginning about the seventh.

The muscles adapted to move the tail laterally are arranged in two sets; the ischio-coccygei externi,' a few fibres of which, in the Horse, are connected with the termination of the rectum and the intertransversales.'

The muscles derived from the vertebral column which serve immediately for the movements of the cranium have nearly the same origins as in the human subject, but are comparatively of much greater strength, owing to the inclined position of the head with respect to that column. They may be divided into such as proceed, 1st, from the atlas; 2nd, from the axis; and, 3rd, from the posterior cervical vertebræ and ligamentum nucha. To the first set belong

The rectus posticus minor,'' rectus anticus,'' rectus lateralis,' and obliquus superior.'

The muscles derived from the axis are the rectus posticus major' and the obliquus inferior.'

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The complexus' commences from the prezygapophyses of the third cervical vertebra, continues its origin from all those of the neck below that point, as well as from those of the first dorsal: also by a strong tendon from the transverse processes of the second and third dorsal vertebræ: from these origins it runs forward to be inserted by a strong round tendon into the super-occipital close to its fellow of the opposite side: in this course it is connected by numerous tendinous processes with the ligamentum nucha.

The trachelo-mastoideus' arises from the oblique processes of the third, fourth, fifth, sixth, and seventh cervical and first dorsal vertebræ, and from the transverse processes of the second and third vertebræ of the back; it runs forward external to the lastmentioned muscles to be inserted by a strong tendon into the paroccipital. The above muscles are overlapped by the 'splenius capitis,' which, arising by strong tendinous processes from the spinous processes of the two superior dorsal and two last cervical, and also extensively from the ligamentum nuchæ, runs forward to be inserted into the transverse processes of the fifth, fourth, and third cervical vertebræ, and into the transverse ridge of the superoccipital.

The muscles of the ribs and sternum present, in the Horse, a disposition little differing from that of the corresponding muscles in Man they are the scaleni,' the intercostals,' the 'levatores costarum,' the serratus posticus,' d, and 'serratus anticus,' l, and the triangularis sterni,' the two latter of which must be regarded as depressors of the ribs, and consequently acting the part of muscles of expiration.

The walls of the abdomen are composed of five pairs of muscles, to which the same names are applicable as are bestowed upon them by the anthropotomist; but the rectus abdominis is much more extensively developed. Arising from the os pubis, it passes forward enclosed in its usual sheath to be inserted into the ensiform cartilage and into the cartilaginous terminations of the third, fourth, fifth, sixth, seventh, eighth, and ninth ribs, and also into the sternum between the cartilages of the third and fourth ribs. There are even fleshy fibres derived from this muscle prolonged as far forward as the articulation between the first rib and the sternum.

Muscles of the anterior extremity. The trapezius' consists