BRANCH CHORD AT /I; CLASS PISCES: THE FISHES 269 



there is given off a large nerve, the vagus, which sends 

 branches to the lateral line organs on either side, and 

 extends backward to the stomach and viscera. 



For further study of the nervous system see Parker's 

 ' Zootomy, ' ' pp. 1 2 2-1 30. 



Make a drawing of the nervous system as worked out. 



TECHNICAL NOTE. To make a good skeleton immerse a fresh 

 or preserved specimen for some time in a hot soap solution. When 

 the muscles have commenced to soften remove the body from the 

 solution, pick the flesh away, and leave to dry. 



Note that the main axis of the skeleton is composed of 

 vertebra placed end to end. How many vertebrae are 

 there ? What vertebra: bear ribs f The ribless ones 

 beyond the body-cavity are called caudal vertebra. Note 

 the inter spinal bones which support the fins, with large 

 muscles on either side to control their action. Note that 

 the group of bones supporting the pectoral fin is attached 

 to the back of the brain -case and makes up the shoulder 

 girdle. The ventral fins are attached to a rudimentary 

 pelvic girdle^ attached in front to the shoulder girdle, as 

 the shoulder girdle is in turn attached to the skull. It 

 will be seen that the sunfish has no neck and we may say, 

 also, no back. Its skeleton consists only of a tail attached 

 to the skull. The brain-case is made up of a number of 

 bones closely joined together. From it is suspended the 

 lower jaw, which comprises a number of bones but loosely 

 attached to each other. Overlying these is the system 

 of membrane bones already mentioned, including the 

 opercle or gill-cover. 



For a detailed study of the fish-skeleton see Parker's 

 "Zootomy," pp. 86-101, or Parker and Hasvvell's 

 4 * Zoology, " vol. II. pp. 183-195. 



Life-history and habits. The sunfish or 4< pumpkin- 

 seed" lives in quiet corners of the brooks and rivers, 

 preferably under a log or at the root of an old stump. It 



