THE YELLOW PERCH 



311 



but recent experiments seem to show that some, at least, are 

 capable of appreciating sound- vibrations. The ears also serve 

 as organs of equilibration, by aid of which the fish is able to 

 maintain its balance. The sense of touch is located in the 

 skin generally, and in the lateral-line organs. The sense of 

 taste is not greatly developed in the perch, and the eyes 

 are not adapted for vision at any great 

 distance. The organ of smell of fishes is 

 peculiar among vertebrates in that it has 

 no connection with the respiratory system. 



The muscular system con- 

 sists principally of a long, 

 thick muscle on either side, 

 stretching from head to tail. 

 In the young fish this muscle 

 is divided into muscular seg- 

 ments extending vertically 

 and corresponding in number 

 with the vertebrae. As the 

 young fish begins active exist- 

 ence the muscle-segments are Fi. 154. Eggs of Perch before and 

 bent and twisted so that for 

 a portion of their extent they 

 seem to run zigzag. 



The Reproductive System. Both the ovary of the female 

 (Fig. 153, 36) and the spermaries of the male are of large size 

 in the mature perch. They open on to the surface at the 

 urinogenital opening (Fig. 153, 37). 



Development. Early in the spring the adult perch, which 

 have spent the winter in the deepest waters of ponds or lakes, 

 often without feeding very much, draw toward the shore. 

 The colors, especially on the males, begin to brighten, till an 

 adult perch in the full glory of his breeding colors is one 

 of the most beautiful objects in his domain. The time of 



after Egg-Laying. Reduced 



(From Bulletin United States Fish Com- 

 mission) 



