444 - Multicellular Animals, Especially Man 



at any particular moment. Most of the pig- any fish provides an excellent preparation in 



ment cells are melanophores, which contain which to study the behavior of the chro- 



black granules, although some are filled with matophores under the microscope. Certain 



granules of other colors. drugs, such as adrenalin, excite the melano- 



A scale scraped from the skin of almost phores to contract, in which case one can 



■>■; 



law • , -v-r*^f^a* 



■EPBteah 





Fig. 24-14. Many fish can change their color and color pattern to match 

 their background. Above, flounder against a background of finely mottled 

 sand and mud. Below, same fish against a background of coarsely mottled 

 shells. (Courtesy of the Fish and Wildlife Service, U.S. Department of the 

 Interior.) 



