THE NECTURUS 27 



Flexor radialis 



This muscle arises on the humerus near the condyle and 

 is inserted on the carpals near the bases of the first and 

 second toes. The insertion is covered by the pronator. 



Ulnaricarpalis 



This small slip is seen extending out from under the 

 flexor ulnaris. It originates on the ulna and is inserted at 

 the base of the third toe. 



Pronator 



Originating on the ulna and extending diagonally, it is 

 inserted on the carpals at the base of the first toe. The 

 supinator is directly opposite it, on the other side of the 

 limb. 



Study the muscles of the anterior limb by sections. 



To understand the relations of the muscles in the an- 

 terior limb, make two cross sections; (1) through the mid- 

 dle of the femur and (2) through the middle of the radius 

 and ulna. Cut through with a sharp pair of scissors, mak- 

 ing a smooth cut. A glass of small magnification is ad- 

 vantageous in examining these sections. If there is any 

 trouble in identification separate the muscles and use the 

 drawings already made as an aid in their recognition. 



MUSCLES OF THE TRUNK 



The body or trunk muscles show many characteristics 

 similar to those of the fish since the myotomes are distinct 

 for the whole length of the body. In higher animals the 

 myotomes and myocommata are absent, being evident in 

 but a few muscles. The midline of the back divides the 

 muscles into a right and a left side, while the linea alba 

 separates them ventrally. Laterally a groove with rows or 



