i6 



FIELD ZOOLOGY. 



Taste. 



The taste organs of insects occur in the roof of the 

 mouth and on the mouth appendages, especially on the 

 palpi.' (Fig. 6.) As with the human tribe, the substance 

 to be tasted must be dissolved and the solution must be 

 brought into contact with the special taste buds. Hence 



it is necessary that the insect 

 shall dissolve its food in the 

 mouth fluids; the taste organs, 

 then, are so situated that they 

 can be brought into the mouth 

 to explore the food or to subject 

 the food to trial before it passes 

 into the mouth. It is not likely, 

 however, that insects are com- 

 pelled to depend entirely upon 

 the method of trial and error in 

 choosing their food. This would, 

 of course, be true if the insects 

 were confronted with a kind of 

 food entirely new in the life 

 history of their kind; but where 

 an insect has been hatched into 

 the environment in which its 

 for many generations, it comes 

 into life with inherited tendencies toward foods that 

 have nourished its ancestors, and against foods that its 

 ancestors have found distasteful or harmful, or strange. 

 Perhaps, as with the human family, the sense of taste 

 contributes to the relish or the pleasure incident to the 

 act of eating, and, therefore, to the secretion of the digest- 

 ive juices. However that may be, the palpi may be 

 observed in active motion during the whole time a 



Fig. 6. — Nerve endings in tip 

 of labial palpus of a fish moth. 

 (Kellogg, after vom Rath; greatly 

 magnified.) 



ancestors have lived 



