xiii.] THE FROG. 227 



a. Each is chiefly made up of a mass, the belly 

 of the muscle, which is nearly white and readily 

 tears into bundles in a muscle which has been in 

 spirit; but is softer, redder, and does not so 

 easily split up in a fresh muscle. 



b. At both ends, in most cases, the belly is replaced 

 by dense shiny tissue forming a tendon. 



c. The tendons are fixed directly or indirectly to 

 some of the neighbouring bones, the less move- 

 able attachment being the origin of the muscles ; 

 the point of attachment to the more moveable 

 bone, its insertion. 



d. The names of the muscles laid bare on the front 

 of the thigh, are 



a. The sartorius: a thin flat riband-like muscle 

 running down the middle ; it arises from the 

 symphysis pubis and is inserted into a tendi- 

 nous expansion (aponeurosis] on the inner side 

 of the knee-joint. 



/?. The adductor magnus: it becomes superficial 

 along the upper two-thirds of the inner border 

 of the sartorius. 



y. The adductor brevis: a little bit of it is seen 

 on the inner side of the adductor magnus, 

 close to the symphysis pubis. 



8. The rectus internus major: a large muscle 

 running along the whole inner side of the 

 thigh; arises from the symphysis pubis below 

 the sartorius and is inserted into the same 

 aponeurosis as that muscle. 



c. The rectus internus minor: a thin muscle lying 



152 



