OTne Anatomy) of tKe FisK 



PERRY BRUCE CLARK 



( 

 -4 



•Tl-ie Yello-W PercK 



i, Dorsal fin- -spinous portion; 2, dorsal fin — soft portion; 3, anal fin — soft 

 portion; 5, anal fin — spinous portion; 4, ventral fin; 6, mandible; 7, maxilla; 8, 

 nostril; 9, teeth; 10, tongue; 11, gills; 12, oesophagus; 13, stomach; 14, pyloric 

 coeca; 15, intestine; 16, spleen; 17, gall bladder; 18, liver; 19, bile duct; 20, anal 

 orifice; 21, air or swim-bladder; 22, auricle of heart; 23, ventricle of heart; 24. 

 kidney; 25, ureter; 26, urinary bladder; 27, uro-genital orifice; 28, spinal column; 

 29, spinal cord ; 30, ribs ; 31, interspinals ; 32, cerebrum ; 33, optic lobe ; 34, cerebellum ; 

 35, olfactory nerve ; 36, optic nerve ; 37, medulla oblongata ; 38, ovary ; 39, aorta ; 

 40, skull or cranium. (Drawing by the author, after Linville and Kelly.) 



In the study of any one animal a 

 knowledge of other animals is of great 

 help, therefore it may be worth while to 

 briefly review the lower animals in the 

 order of their complexity, from their 

 simplest beginning, that of the single cell, 

 up to and including our present subject, 

 the fish. This review being somewhat 



evolutionary in character, it might be 

 added that in trying to follow the course 

 of evolution, we know very little or noth- 

 ing at all of many links in the chain, as 

 great numbers of them are now extinct 

 (many more than are living today) of 

 which no geological record has been 

 found. We can, therefore, only guess 



