22 EXPERIMENTAL PHYSIOLOGY 



on a flat cork or glass plate, and open the abdomen and thorax freely 

 but carefully. Notice the viscera (Fig. 27) heart and lungs, liver, 

 stomach, intestines, ovaries and oviducts or testes, bladder. Cut 

 through the lower end of the rectum and through its attached 

 mesentery. On raising it, two elongated red bodies the kidneys 

 are seen at the back of the abdomen, partly covering the nerves which 

 are passing down to the hind limbs. Remove the kidneys without 

 touching the nerves. Now hold the frog up by its legs so that the 



Iliac ext. 



Tensor fasc. lat. 



Triceps, fern. 



Pyriformis. 



Semimembranosus. Iliofibula. 



Peronens. 



-Tibial ant. long. 



Tendo Achillis. J ! jji$[ 



Tars. ant. 



FIG. 28. Muscles of frog-leg ; dorsal aspect (Gaupp). 



viscera hang towards the head, and cut through the lower end of the 

 vertebral column with strong scissors so as to separate the fore part of 

 the trunk and the viscera from the pelvis and hind limbs. Lay the 

 latter preparation on a clean glass plate or on a piece of paraffined 

 paper on the frog-cork. Note the several muscles which are seen on 

 the front and back of the lower limbs (Figs. 28, 29). 



The thin, flat sartorius is seen crossing obliquely over the front of 

 the thigh. It is readily isolated by cutting the tibial attachment 

 away with a piece of the bone, raising this, and snipping through the 

 fascia on either side of the muscle, thus separating it right up to its 



