The Grasshopper 



343 



pute. Very little direct evidence is available; most of it is circum- 

 stantial. Many authors and experimenters hold that insects recognize 

 colors only as shades of gray, much as a color-blind person does. On 

 the other hand, not a single experiment to prove color vision has demon- 

 strated such a fact. It is not a necessary correlation that because 

 flowers are colored, insects see colors. Half of the good pollinators are 

 night fliers. 



TOUCH 



The sense of touch is probably very highly developed in most in- 

 sects as there are sensory tactile hairs over the entire body, as well as 

 antennae, palpi, and cerci which are also special tactile organs. 



Fig. 224. 



A. The common cricket, Gryllus Pennsylvanicus, female. Line indicates 

 natural size. 



B. Oblong leaf-winged Katydid, Amblycorypha oblongifolia, female. (From 

 Kellogg's "American Insects," by permission of Henry Holt & Co.) 



TASTE 



The sense of taste is located in the sensory hairs; in the micro- 

 scopic elevations borne upon the tongue or hypopharynx, on the epi- 

 pharynx (which lies on the roof of the pharynx, and is something like 

 the palate in higher animals), and on the maxillary and labial palpi. 

 From the experiments so< far performed it seems insects can detect tastes 

 that man cannot. 



SMELL 



Insects may depend upon the sense of smell to find their food more 

 than upon sight, but the usual experiments to demonstrate this are far 

 from satisfactory. The cutting away of antennae with the attendant 



