AVES. 



291 



spinous processes of the dorsal vertebrae and 

 from the anterior part of the cervical vertebrae, 

 and these slips diverge to be inserted into the 

 transverse processes, and their appended styles 

 or spurious ribs. 



A superadded muscle, which may be re- 

 garded as a continuation of the preceding, and 

 which corresponds to the increased number of 

 the vertebrae of the neck, passes from the 

 transverse processes of the five superior ver- 

 tebras to the anterior spines of the vertebras 

 immediately anterior a portion of this muscle 

 is shown at 5. 



No. 6 indicates one of the most remarkable 

 muscles in the cervical region of Birds ; it 

 is analogous to the Biventer cervicis of mam- 

 mals, but has a much longer and more 

 distinct middle tendon, a. 6. Its lower or pos- 

 terior venter, b. 6, arises by a tendon, most com- 

 monly from the short spinous processes of the 

 lowest cervical vertebrae, the anterior fleshy 

 part c is inserted into the squamous spine of 

 the occiput. This muscle is well developed 

 in the Ostrich, where it arises as low down as 

 from the last lumbar vertebra, by a long ten- 

 don, which is continued to the cervical region 

 before it joins the fleshy portion, the whole 

 muscle affording a striking example of the 

 peculiar development of the tendinous over 

 the carneous part which characterizes the mus- 

 cular system of Birds. In the Parrots and 

 Raptorial birds, however, the carneous exceeds 

 the tendinous part of this muscle. 



The Complesnts (7) arises from the articular 

 and transverse processes of a variable number 

 of the superior cervical vertebras, and passes 

 obliquely backwards to be inserted into the 

 occiput, crossing exteriorly the upper belly of 

 the preceding muscle. 



The Trachelo-mastoideus (8) arises from the 

 articular processes of the cervical vertebras from 

 the second to the sixth, and is inserted into 

 the posterior part of the basis crunii. 



Anterior to the preceding muscle a portion 

 of the Rectus cupitis antic us major may be 

 seen at 4. This muscle is largely developed, 

 arising from the anterior part of the sixth, 

 seventh, and eighth vertebrae, and inserted into 

 the basis cranii. There are also muscles ana- 

 logous to the Rectus capitis anticus minor, the 

 Recti postici majores et minores, the Obliquus 

 externus or superior, and in the Penguin, a 

 strong tendon is given off from the Trachelo- 

 mastoideus which represents the obliquus in- 

 ferior of the neck. 



When it is remembered that the cervical re- 

 gion of the spine in Birds is subservient and 

 essential to all tlie movements and functions 

 of the bill, as a prehensile instrument, and a 

 cleanser of the plumage, we cannot sufficiently 

 admire the endowments of length, flexibility, 

 and muscularity, by which it is enabled to 

 fulfil the important functions of an additional 

 extremity. 



In the caudal region of the spine the fol- 

 lowing muscles present themselves. On the 

 dorsal aspect, the Levator coccygis (10) ex- 

 tends from the transverse processes and lower 



extremity of the sacrum to the superior spines 

 of the coccyx and the base of the last or 

 plough-share vertebra. This muscle may be 

 regarded as a continuation of the spinalis dorsi. 

 Beneath it are found strong Interspinales mus- 

 cles. 



The Quadratic coccygis (11) arises from the 

 transverse processes of the coccygeal vertebras 

 and is inserted into the shafts of the rcctrices 

 or tail-quills, which it separates and raises. 

 On the lateral aspect we find the Pubo-coccy- 

 geus (12) arising from the posterior margin of 

 the pubis, and inserted also into the shafts of 

 the exterior rectriccs; it is by means of these 

 muscles in conjunction with the two preceding 

 that the Peacock spreads its gorgeous tail. 



The Ilio-coccygeus (13) extends from the 

 posterior margin of the ilium to the last coccy- 

 geal vertebra, and to the small inferior tail- 

 feathers. 



On the ventral or inferior aspect of the tail, 

 the muscles are in general more feebly developed 

 than on the opposite side, except in the Wood- 

 peckers, where the tail, by means of its stiff and 

 pointed quill-feathers, serves as a prop to sup- 

 port the bird on the perpendicular trunks of trees 

 on which it seeks its food. In these the Isc/iio- 

 coccygeus (14) is of large size, extending from 

 the lower edge of the ischiadic tuberosity, and 

 from the transverse processes of the anterior 

 coccygeal vertebras to the inferior spines of the 

 posterior coccygeal vertebras, and to the sides 

 of the last compressed or plough-share bone. 



The Depressor coccygis (15) extends from 

 the ventral aspect of the bodies of the anterior 

 coccygeal vertebras to the inferior spines of the 

 posterior and to tlie base of the last vertebra. 



Of the Muscles of the head those which are 

 attached to it for its general motions have 

 already been described ; the remaining mus- 

 cles of this part are devoted to the movements 

 of the jaws, the tongue, the eye, and the ear. 

 The cutaneous muscles of the face are usually 

 described as being entirely deficient, and the 

 only ones that can be regarded as belonging 

 to this series are the slips of panniculus car- 

 nosus, analogous to an occipito-frontalis (16), 

 winch are chiefly developed in order to elevate 

 the crest-feathers in those birds which possess 

 that ornament ; there are also cutaneous slips 

 which belong more properly to the organs of 

 hearing, and which raise the auricular circle of 

 feathers in the Owls, Bustards, &c. 



The muscles of the jaws are chiefly mo- 

 dified in relation to the moveable condition 

 of the upper mandible and tympanic bone, 

 and the subserviency of the latter to the actions 

 of these parts. 



The Temporalis (17) fills the temporal fossa, 

 which consequently indicates the bulk of that 

 muscle in the dry skull. It arises from a 

 greater or less extent of the temporal and 

 parietal bones, and, as it passes within the 

 zygoma, becomes closely blended with the 

 Masseter; the united muscles derive an acces- 

 sion of fibres from the lower part of the 

 orbit, and are inserted into the raised superior 

 margin, representing the coronoid process ; 



u 2 



