524 



RUMINANTIA. 



or ten such bundles may be remarked in 

 different species. In the first place we have 

 a broad band extending from the fore-part of 

 the neck, and spreading toward the lips and 

 forehead ; this constitutes the musculus cu- 

 taneous faciei. Again, it is very strongly 

 marked at the neck, especially in the Sheep ; 

 here it is denominated the m. cutan. colli. In 

 other domestic animals of the non-ruminant 

 kind, such as the Dog, Cat, and Pig, this se- 

 cond division of the fleshy envelope is still 

 more striking. Over the shoulder of the Ox 

 there is a third layer of thickened fasiculi 

 (m. cutan. humeri) ; and lastly, we find a 

 highly developed mass, taking its origin from 

 the fascia lata of the thigh immediately above 

 the patella, and proceeding forward, the 

 fibres radiate toward the scapula in front and 

 the abdomen below ; this is the m. cutan. 

 maximus sen abdominis. The insertion of the 

 panniculus is directly into the skin, which 

 everywhere covers it, and " on this texture it 

 can alone act, seeing it is completely isolated 

 from the deeper seated parts, by an universal 

 layer of fascia, which thus enables it to slide 

 more freely upon them. When in action, the 

 fibres throw the skin into folds that form 

 right angles to their general course ; the 

 chief points from which they act being the 

 angle of the jaw, the scapula, the patella, and 

 the pubis."* The principal function appears 

 to be that of serving as an instrument of de- 

 fence. By its action animals have the power 

 of jerking and shaking the skin, thus removing 

 irritating matters, also of erecting bristles 

 and spines as instanced by the defensive 

 armature of the Hedgehog, and in aiding 

 the process of lactation, as obtains in the 

 Marsupiatae. Were it not for the constant 

 and involuntary action of the muscle, the 

 torture (to which many animals, particularly 

 cattle, are subjected, from the stings and 

 bites of flies and other insects), would become 

 intolerable, and consequently we find 

 those creatures which are most exposed to 



their injurious attacks a preponderating de- 

 velopment of this structure. 



In the same category as the above cutaneous 

 muscles may be associated themusculus prepu- 

 tialis sen umbilicus, the superficial orbicularis 

 palpebrarum, and certain of the complicated set 

 of organs which act upon the concha and scu- 

 tum of the external ear. Of the latter, sixteen 

 pairs have been described as common to the 

 Ox, and nearly as many have been indicated in 

 the Sheep. In both genera they surround the 

 ear on all sides, and offer similar characters in 

 respect of relative size and position. By their 

 reciprocal action the auricular appendage is 

 turned in every direction, as well as rotated 

 upon its own axis ; it is likewise expanded 

 and contracted by such of them as proceed 

 from one part of the concha to another. 

 The orbicular muscle of the eyelid (5,/g. 349.) 

 is thick and fleshy, and its action is aided above 

 and below by thin strata of fibres coming 

 from the panniculus; these are independent 

 of the ordinary elevators and depressors of 

 the lid. 



Muscles of the head and trunk. Referring 

 to the accompanying figures for a general 

 outline of the superficial and deep muscular 

 layers included in the above division, we 

 propose to treat in detail of such muscles as 

 acquire a particular interest in respect of 

 their position or importance in a physiological 

 point of view. 



In the clavicle-bearing mammals the tra- 

 pezius consists of two parts, an anterior or 

 clavicular portion, and a posterior or scapular 

 division ; but in ruminants and other quad- 

 rupeds which are unprovided with these bones, 

 the posterior section is alone represented by 

 the trapezius properly so called(10, 1 l,j#g.349). 

 On this account it is comparatively small and 

 restricted in its superior attachments, the 

 fore-part being narrow and connected to the 

 elastic ligament of the neck and the dorsal 

 in portion, which is somewhat shorter and 

 thicker, becoming attached to the spinous 



Fig. 349. 



View of the superficial muscles of the trunk in the Ox. (From Gurlt.) 



1, orbicularis oris ; 2, levator labii superioris ; 3, zygomaticus ; 4, depressor palp, inferioris ; 4 *, risorius 

 santorini ; 5, orbic. palpebrarum ; 5 *, masseter ; 6, corrugator superciliorum ; 7, depressor auriculae ; 

 8, 8, 8, deltoides ; 9, sterno-maxillaris ; 10, 11, trapezius; 12, latissimus dorsi; 13, pectoral is major; 

 14, obliquus externus ; 15, glutaeus maximus ; 16, tensor fasciae latae ; 17, 18, biceps femoris. 



* Mercer, On the Structure and Uses of the Panniculus carnosus, Med. Gazette, 184041, p. 346. 



