MYOLOGY or REPTILES. 219 



strips Iroin the second and tliird cervical diapopliyses, inserted 

 into the under ])art of the scapula, indicate the commencement of 

 tlie serratiis vuii/nus aiif.iciis, fig. 141, 21. The mass of muscle, 

 fiji;s. 140, 141, 23, wliich protracts or 'flexes' the fore-arm, aris- 

 ing from the fore and inner part of the glenoid cavity and from 

 tlie fore part of tlie luimerus, represents the blcrps and hraclikdh 

 niterims. Tlie retractor or extensor mass, ib. 24, answers to 

 tlie divisions of the triceps. On the aiitibrachiam the flexor of 

 the wrist is divided into a 'radial,' fig. 141, 25, and ' idnar,' 

 fig. 140, 2G, i)ortion ; as is likewise the extensor, of which, 27, 

 fig. 141, represents the extensor c/irjri idnarh, and 28 the extensor 

 carpi. riid/'aUs : 29 is the flexor cliijitoram coinmunia, and 30 the 

 extensor diijitorum cornrnnrds. 



The pectoreilis, fig. 141, lo, is represented in the pelvic limb 

 by the muscle, ib. 3C, wliicli arises from the ischiopubic syni- 

 }ihysis, and is inserted into the front and inner part of the 

 head of the tibia. This mass in higher reptiles becomes dif- 

 ferentiated into the pectineus, the adductors, and the i/racdis ; 

 it depresses and adducts the pelvic liml). Its chief antagonist 

 is marked 36 in fig. 140. It rises from the ilium, and is inserted 

 into the lower and outer part of the femur, and also into the 

 outer part of the head of the, tibia; it corresponds by its origin 

 with 22 in tlie fore limb, and becomes develo2)ed into gluteus 

 exteruus Mxd ' tensor fascice fenwris^ m Mammals. The fasciculi 

 wliich correspond with 11, in the fore-limb are 37 and 32, fig. 140; 

 tliey arise from fascia connected with tlie transverse processes of 

 the third and fijurth caudal vertebra^, and are inserted into the 

 middle and back part of the femur. The muscle, 31, which arises 

 from the fore part of the ilimri, and is inserted into the upper 

 third of the femur, rejieats the anterior filn-es of 22 in the scapular 

 limb. The chief difference is that the pnjtractors, 31, and retrac- 

 tors, 32 and 37, of the thigh are more distinct from the abductor 

 and levator, 36 ; and that this has a more ad^^antagcous insertion 

 fir its office Ijy being extended to the second segment of the 

 limb. The retractors, 32, 37, act like the latissiinus dorsi 11 : their 

 origin is in connection with the vertebral or axial system : they 

 l^ecome developed in the pelvic limb of liigher animals into parts 

 of the ' glutei ' and ' pyriformis.' 



Tlie protractors or flexors of the thigh, 34, 3;j, which answer t(j 

 those of the arm, 23, arise from the fore and under part of the 

 ilium, and are inserted into the fore and upper end of the tibia. 

 The muscle, fig. 141, 35, which passes to the inner side of the head 

 of the tibia, answers best to the surtorius ; the larger mass on its 



