1897] MICROSCOPICAL JOURNAL. 19 



i\\G liinb muscles. The spinal muscles are plainly homo- 

 logous with those of the teleost; for they are similarly 

 located. In the post-abdomeu they make up the bulk of 

 the flesh and are closely related t«) neural and haenial 

 spines ; and in the trunk they are related to neural spines 

 dorsally while ventrally they compose a large portion of 

 the wall of the body cavity. They are also segmented, 

 each myotome being made up of short fibres parallel in 

 their arrangement and corresponding precisely with the 

 number of the vertebrae. The limb muscles are rela- 

 tively insignificant in the salamander whose limbs are 

 email, though really much used, but they are homologous 

 with the ver}' important limb muscular system as it 

 exists in its highly elaborate state in the mammals. The 

 €Xact identification of the muscles of the limb will hardly 

 be possible in this course, but a number of points can be 

 made out. The muscles are seen to consist of a muscr- 

 lar central portion the belly, and at the end a tendon 

 which in some cases is quite long. 



The muscles have two points of attachment, one the 

 origin nearer the back-bone; a distal one the insertion far- 

 ther from the spine. The shortening of the muscle 

 causes it to pull on its tendon and thus to move the 

 bones on their joints. The muscles are placed on oppo- 

 site sides of the limb so that some bend qx flex it, while 

 others antagonize these and extend \i again. 



11. Fine Structure of Striated Muscle. — Cut out 

 one of the small muscles of the limb, place it on a slide, 

 surround it with glycerine, tease it carefully into its 

 component fibres, taking care not to twist them; after 

 spreading the muscle out as well as possible, cover and 

 examine with a low power. You can now recognize more 

 clearly that the organ is made up of parallel short pieces, 

 imbedded in a network of minute fibres of ivhite fibrous 

 connective tissue, trace these latter toward the tendon and 



