528 



RUMINANTIA. 



whole length of the neck to its insertion, it is 

 obvious that a great proportion of the mus- 

 cular fibres would have been useless ; for as 

 these have the power of shortening themselves 

 by their contractility only one-third of their 

 own length, if they had been continued from 

 end to end in the slerno-thyroidei, they would 

 have been able to draw the larynx and os 

 hyoides one-third of the way down the 

 neck ; such displacement, however, is neither 

 required nor indeed compatible with the me- 

 chanical connections of the parts ; but, by the 

 intervention of long and slender tendons, the 

 quantity of the contractile fibre is duly appor- 

 tioned to the extent of motion required for 

 the larynx and os hyoides. The muscle ana- 

 logous to the omo-hyoideus of other animals, 

 is adjusted to its office by a different and 

 more simple modification ; instead of having 

 a remote origin from the shoulder-blade, its 

 fixed point of attachment is brought forward 

 to the nearest bone (the third cervical ver- 

 tebra) from which it could act upon the os 

 hyoides with due power and extent of con- 

 traction. Its insertion is by a small round 

 tendon." 



The muscles of the back and tail present 

 few deviations worthy of remark. The spin- 

 alls and longissimus dorsi exhibit the same 

 attachments as in Solipeda. The sacro-lum- 

 balis is proportionately strong in ruminants. 

 The semispinalis col/i, according to the ob- 

 servations of Meckel, is very largely developed 

 in the Camel, originating from the spinous 

 apophyses as well as from the transverse 

 processes of the five or six anterior dorsal 

 vertebras. These additional points of origin, 

 while they afford a greater leverage power, 

 constitute at the same time an important pe- 

 culiarity in this long-necked animal. 



The diaphragm, which is present in allmam- 

 mifera, exhibits three openings for the passage 

 of the aorta, oesophagus, and inferior vena cava. 

 A very remarkable feature exists in connection 

 with this muscle in the Camelidse. It consists 

 in the presence of a small bone situated near 

 the margin of the central tendon. Meckel states 

 that Dr. Jceger was the first to direct attention 

 to this anomaly in the Dromedary and in the 

 Vicugna*, the observation being subsequently 

 confirmed by Dr. Leuckart and himself. In 

 the two-humped orBactrian Camel its presence 

 was overlooked by the original discoverer, 

 but afterwards ascertained by Meckel to oc- 

 cur in this species also. The bone offers 

 slight variations according to the age of the 

 individual ; it is thin and rather more than 

 two inches long in the adult Camel ; in the 

 Vicugna it is but feebly developed. Its so- 

 lidity is not acquired until a late period, for, 

 in a Dromedary about two years old, the car- 

 tilaginous matrix only was discernible. In 

 conclusion it may be said that this osseous 

 formation is apparently designed to give sup- 

 port to the diaphragm, which is of great bulk 

 in these animals. 



* Syst. der vergleich. Anat. (Fr. edit., torn. vi. 

 p. 212.) 



Muscles of the shoulder and fore-limb. The 

 trapezlus has already been considered. The 

 levator angulis scapnlce (8, fig. 350.) varies little 

 from the ordinary mammiferous type. The 

 rhomboideus (9) is usually represented by two 

 muscles, r. minor and r. major; the former, 

 sometimes called the superior, arises in the 

 Sheep from the ligamentum nuchae as far 

 forward as the second vertebra of the neck, 

 and the latter, or rhomboideus inferior, proceeds 

 from the spines of the first two or three dor- 

 sal vertebrae, the fibres of both converging to 

 be inserted into the upper border of the sca- 

 pula. In the Horse the muscle is single, and 

 extends forward to the occiput, but is only 

 connected superiorly to the cervical ligament. 

 It is very feebly developed in the Camel, pass- 

 ing only from the spines of the two anterior 

 dorsal vertebrae to the posterior angle of the 

 scapula. In certain Pachydermata and in the 

 Cetacea its appearance is still more insig- 

 nificant, but it is particularly large in the 

 carnivorous mammal? and in the Ornithorhyn- 

 chus. In the Giraffe it is inserted, like the 

 largely developed serratus major, into the car- 

 tilage surrounding the base of the scapula; and 

 in reference to the use of this structure Prof. 

 Owen observes that " as the fore-part of the 

 trunk is, as it were, slung upon the two great 

 serrati muscles which principally support the 

 weight of the remarkably deep chest of the 

 Giraffe, the interposition of the elastic car- 

 tilages between the upper attachments of the 

 muscles and the capitals of the bony columns 

 of the two fore-legs, must be attended with 

 the same advantage as is obtained by slinging 

 the body of a coach upon elastic springs." * 

 The serratus magnus or major (10, 10) is ex- 

 ceedingly strong in this order. In quadrupeds 

 generally, it differs from the human subject in 

 presenting a cervical attachment in addition 

 to its costal connection. In the Sheep it has 

 no less than thirteen bundles of origin, eight 

 of which come off from a corresponding num- 

 ber of the superior ribs, the remaining five 

 proceeding from the transverse apophyses of 

 the third to the last cervical vertebra inclu- 

 sive. In other ruminants there is a slight 

 numerical variation in regard to the fleshy 

 digitations, but their general disposition is the 

 same, being in all cases subsequently united 

 and implanted into the base of the scapula, 

 there forming, in conjunction with the tra- 

 pezius, a sling-like support to the anterior 

 extremity. The serralus minor has an ar- 

 rangement in mammifera similar to that of 

 its anologue, the lesser pectoral of the human 

 subject ; but in the latter it is inserted into 

 the coracoid apophysis of the scapula, while 

 in the former it is usually connected to the 

 humerus. In many carnivorous, edentate, 

 and marsupial families this muscle is entirely 

 wanting. 



The latlssinnts dorsi (12, fig. 349.) is some- 

 what feebly developed in ruminants, but its 

 attachments are similar to those in Man. The 

 pectoralis major ( 1 3, fig. 349) is proportionately 



* Memoir, /. c. 



