136 American Fisheries Society 



may distinguish between taste and smell on the ground 

 that taste is concerned with substances in liquid solu- 

 tions while smell has to do with gases and vapors. But 

 we now know (Parker and Stahler, 1913), that the gases 

 and vapors that affect our sense of smell are first dis- 

 solved in the fluid that moistens the lining of the nose. 

 Thus both the organs of taste and smell are affected by 

 substances in solution, and there is no difference between 

 them on this score. 



But these senses differ in several ways. First, the 

 organs of taste are affected by things in contact, that of 

 smell by gases or vapors which come primarily from 

 things at a distance. Second, the organs of taste are 

 affected only by substances in relatively concentrated 

 solutions, the organ of smell by substances very greatly 

 diluted. Parker and Stahler (1913), found that pure 

 ethyl alcohol could be smelled when its molecular concen- 

 tration was only about one twenty-four thousandth that 

 necessary to give a sensation of taste. When quinine, 

 the substance having the strongest known taste, is com- 

 pared with mercaptan, the substance having the strong- 

 est known smell, the difference is still more striking. 

 To give any sensation of taste the quinine must have a 

 molecular concentration 44,000,000 times that of the mer- 

 captan that man is just able to smell. Third, while we 

 know but four tastes we perceive a very large number 

 of odors. 



In fishes the organs of taste and smell are of course 

 affected by substances in solution, for all things capable 

 of affecting them are dissolved in the water. We may 

 therefore expect these senses in fishes to operate very 

 much as they do in man. Things that fishes taste must 

 be in contact ; they are usually tasted and felt at the same 

 time. They must affect the organ of taste in relatively 

 concentrated solution. Things that are smelled may be 

 at a great distance. They are smelled without being 

 touched. Their odorous portions reach the fish through 

 the water and must often be greatly diluted. That there 

 are but few qualities of taste in fishes as in man and 



