198 



THE FROG-THE PLATANA 



Third Day 



Muscular System and Vascular System (continued), and 



Nervous System (part) 



A. Muscular System. 



In order to facilitate the location of the veins and arteries of the hind-limbs, 

 it is necessary to make out the following muscles : — 



1. Muscles of the Thigh (ventral surface) : 



(a) The sartorius, a long flat muscle arising from the lower end of the ilium, 



and inserted into the inner side of the head of the tibia. 



(b) The vastus internus, a large muscle arising from the ventral and anterior 



border of the acetabulum, and lying partly under the sartorius on the 

 outside of the thigh. 



(c) The rectus internus major, a large muscle arising from the ischium, 



occupying the inner side of the thigh and inserted into the head of the 

 tibia. It is covered distally by the sartorius. 



(d) The adductor magnus, a large muscle arising from the pubis and ischium. 



It lies between the sartorius and the rectus internus major, and is con- 

 cealed by these muscles distally where it becomes inserted into the 

 femur. 



2. Muscles of the Shank (ventral surface) : 



(a) The gastrocnemius, a large spindle-shaped muscle forming the calf of 

 the leg. It arises mainly from the hinder side of the distal end of the 

 femur ; and it ends in the long and slender tendo Achillis, which passes 

 under the ankle joint and into the sole of the foot. 



Vastus internus 

 Sartorius 



Tibialis, anticus 

 Tibio-fibula | 



I Extensor 



1 Rectus internus major ; Tibialis posticus 

 Adductor tnagnus Gastrocnemius 



Sartorius Extensor cruris 



Rectus anticus femoris ,' Tibialis anticus ; 



Vastus internus 



Adductor magnus i 



Rectus internus minor 



ribialis posticus 



Rectus internus major 



Pig. 68. — A. Muscles of the Left Hind-limb of Rana ; and B. of Xenopus, from 



the ventral surface. 



