Sensory Discrimination : the Chemical Sense 101 



the queen be replaced in the honey space, removed from the 

 rest of the hive, the bees will quiet instantly, before the smell 

 has had time to diffuse itself. Also, bees sometimes behave 

 as if they had lost their queen when she is only put in a cage, 

 and her odor is perfectly accessible (72). 



It is clear that bees as well as ants are capable of dis- >*/ 

 tinguishing a considerable number of smell qualities. Prob- 

 ably the same thing is true of the social wasps. In the 

 solitary wasps, however, we find less evidence of a highly 

 developed sense of smell, or rather of a great variety of smell 

 reactions, and the solitary bees are very likely less influenced 

 by smell than the social bees. In the interesting study of the 

 solitary wasps by Mr. and Mrs. Peckham, it appears that 

 sight plays a far more important role than smell for these 

 insects and the return to the nest in particular seems to be 

 almost entirely an affair of sight (322, 323). In general 

 the greatest development of qualitative variety in the sense of 

 smell is found in the social Hymenoptera, and is probably 

 a product of the social state. Perris, however, noted that 

 the solitary wasp Dinetus was much disturbed in finding its 

 nest hole if he had placed his hand over the hole during 

 the wasp's absence, and thought the odor of his hand was 

 distracting to the insect (324). 



32. The Chemical Sense in Vertebrates 



Although the vertebrates stand at the head of the animal 

 kingdom, yet in point of complexity of structure and behav- 

 ior the lowest vertebrate is far below the highest members p 

 of the invertebrate division. When we undertake to study 

 the responses to special stimulation displayed by this 

 same lowest vertebrate, the little Amphioxus or lancelet, 

 it is like going back to the earthworm. The only kind of 

 evidence that contact, chemical, and temperature stimuli 



