FISHES 249 



Although many young salmon fall prey to other fish the majority 

 find their way back to the ocean where they reach adult life, and, 

 if they escape the canner's machines, live to repeat the self-sacrifice 

 of their parents. 



Adaptations. The study of the fish reveals an animal, first of 

 all adapted for aquatic life, and nearly all features of its structure 

 and habits tend to this result, as the following summary will show. 



SUMMARY OF ADAPTATIONS 



For Locomotion in Water. 



1. Shape of body, slimy secretion. 



2. Scales, fins. 



3. Flexible spinal column and powerful muscles. 



For Life in Water (see above, also). 



1. Gills for respiration. 



2. Air bladder, to regulate depth. 



3. Lateral line to determine pressure. 



4. Structure of eye, spherical lens. 



For Protection. 



1. Color, dark above, light below. 



2. Scales, spines, teeth. 



3. Speed, to escape enemies. 



For Food Getting. 



1. Location and size of mouth. 



2. Shape and location of teeth. 



3. Wide gullet and powerful digestion. 



4. Speed. 



COLLATERAL READING 



General description and structure: American Food and Game Fishes, 

 Jordan, pp. 364-367; Fishes, Chap. XXXIII, Jordan, p. 508; Fishes, 

 Chap. X (adaptations), Jordan, pp. 51-78; Familiar Fish, McCarthy, 

 Chap. 7; American Natural History, Hornaday, pp. 380-387; Life in 

 Ponds and Streams, Furneaux, p. 353; General Zoology, Linville and 



