724 



SOLIPEDA. 



nates by forming as many tendons as there 

 are caudal vertebrae without transverse pro- 

 cesses. These tendons are received into 

 sheaths resembling those upon the upper sur- 

 face of the tail, and are inserted successively 

 into the base of each caudal vertebra, be- 

 ginning about the seventh. 



3. The Intcrspinales inferiores {sub-caudalcs, 

 inter-coccygeus of Vicq d'Azyr). These are 

 situated beneath the mesian "line of the tail. 

 They commence underneath the articulation 

 between the first and second caudal vertebrae, 

 and form an elongated fleshy belly, which, in 

 some quadrupeds that have the tail largely 

 developed, become first of all implanted into 

 V-shaped hones derived from the fourth, fifth 

 and sixth vertebras of the tail : they receive, 

 moreover, from time to time additional fleshy 

 slips, which go on continually diminishing in 

 size, and give off tendons to be inserted suc- 

 cessively into the inferior aspect of the base of 

 each caudal vertebra. 



4. The pubo-coccygeus (pubo-sous-caudien). 

 This is a thin muscle, derived from the whole 

 extent of the upper margin of the pelvis, and 

 having the appearance of a fleshy membrane, 

 the fibres of which are gradually collected into 

 one point to be inserted beneath the tail into 

 tubercles situated upon the base of the fourth 

 and fifth vertebras. The action of this muscle 

 will produce an effect similar to that of the 

 ileo-coccygeus. 



The muscles adapted to move the tail later- 

 ally are arranged in two sets. 



1. The ischio coccygeus externus (ischio- 

 caudien) arises from the posterior or internal 

 surface of the ischium, a little below and be- 

 hind the cotyloid cavity, from which origin it 

 runs backwards to be inserted into the trans- 

 verse processes of the anterior caudal vertebrae. 

 This muscle is improperly called by Stubbs 

 the levatorani, because in the horse a few fibres 

 of it are connected with the termination of 

 the rectum. 



2. The intertransversa'les (intertransversal of 

 Vicq d'Azyr) extend in the form of mus- 

 culo-aponeurotic layers over all the transverse 

 processes that are developed in the caudal 

 region, their tendons of insertion being most 

 distinctly seen upon the upper surface of the 

 tail. 



In animals that have the muscular appa- 

 ratus of the tail completely developed the 

 muscles are found to consist of eight distinct 

 sets, viz., two superior, two lateral, and two 

 inferior. In the horse some of these are de- 

 ficient, or exist only in a rudimentary con- 

 dition. To see them in their full state of de- 

 velopment they must be examined in animals 

 provided with long and mobile tails, such as 

 the prehensile-tailed monkeys, the opossums, 

 the lion, and, more especially, in the kangaroo 

 and beaver. 



Muscles derived from the spinal column which 

 serve immediately for the movements of the 

 cranium. These 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 the ver- 



tebral column. They may be divided into 

 such as proceed, 1st, from the atlas ; 2nd, 

 from the axis; and, 3rd, from the posterior 

 cervical vertebrae and ligamentum nuchae. 

 To the first set belong 



1. The rectus capitis posticus minor, or rather 

 medius, arising, as in the human subject, from 

 the atlas ; from this origin it runs to be in- 

 serted by a short and broad tendon into the 

 occiput. 



The other muscles belonging to the atlas 

 namely, the rectus anticus, the rectus lateralis, 

 and the obliquus superior offer the same 

 position as in the man. 



The muscles derived from the axis viz. 

 the rectus posticus major and the obliquus in- 

 ferior are likewise similarly disposed in all 

 quadrupeds. ' 



The muscles arising from the other cervical 

 vertebrae are 



The complcxus, which, commencing from 

 the upper oblique process of the third ver- 

 tebra of the neck, continues its origin from 

 all the oblique processes of the neck below 

 that point, as well as from the upper oblique 

 process of the first vertebra of the back, also 

 by a pretty strong tendon from the transverse 

 processes of the second and third dorsal ver- 

 tebrae ; from these origins it runs forwards to 

 be inserted by a strong round tendon into 

 the occiput close to its fellow of the opposite 

 side : in this course it is connected by numer- 

 ous tendinous processes with the ligamentum 

 nuchae. That portion of the complexus usu- 

 ally distinguished by the name of digastricus 

 coili is in the horse undistinguishable as a 

 distinct muscle. 



The trach elo-mastoidens, or complexus minor, 

 arises from the oblique processes of the third, 

 fourth, fifth, sixth, and seventh cervical and 

 first dorsal vertebrae, and from the transverse 

 processes of the second and third vertebrae 

 of the back ; it runs forwards external to the 

 last-mentioned muscles to be inserted by a 

 strong tendon into the mastoid apophysis of 

 the temporal bone. The above muscles are 

 overlapped by the 



Splenius capitis {cervico-mastoidcii) , which, 

 arising by strong tendinous processes from 

 the spinous processes of the two superior 

 dorsal and two last cervical, and also exten- 

 sively from the ligamentum nuchae, runs for- 

 ward to be inserted into the transverse pro- 

 cesses of the fifth, fourth, and third cervical 

 vertebra, and into the transverse ridge of the 

 occipital bone. It is remarked by Cuvier that 

 in carnivorous quadrupeds the splenius is not 

 inserted into the transverse processes of the 

 cervical vertebrae as it is in herbivorous animals 

 and in the human subject, in which the latter 

 portion is sometimes sufficiently distinct to 

 obtain the name of splenius colli in contra- 

 distinction to the splenius capitis. It is like- 

 wise remarkable that in the camel, if the 

 splenius exists at all, it is extremely thin and 

 difficult to display by dissection. 



Muscles of the ribs and sternum. The mus- 

 cles derived from and inserted into the ribs 

 and sternum are found in all quadrupeds to 



