Sensory Discrimination : the Chemical Sense 97 



probably distinct, though there is no experimental proof of 

 the fact; the individual smell of an ant's own footsteps; 

 a possible distinction, in some species, between the smell of 

 the outgoing and that of the incoming paths ; and the different 

 odors which seem to be responsible for the discrimination be- 

 tween nest mates and foreigners. If it is true, as Fielde 

 maintains, that loss of the eighth and ninth segments of the 

 antennae renders an ant incapable of caring for the young, 

 then the recognition of larvae and pupae does depend upon a 

 specific odor (118). Forel makes an interesting distinction 

 between the sense of smell in insects with immovable anten- 

 nae and the same sense where the antennae, as in ants, can 

 be moved about over objects. In the former case it is as 

 with us a qualitative sense pure and simple, giving informa- *., 

 tion of objects at a distance ; in the latter case it is a contact 

 sense, and may give rise to spatial as well as qualitative per- 

 ceptions. He compares the antennae to a pair of olfactory 

 hands, and points out how such organs may allow of the per- 

 ception of the " smell form" of objects (132). 



29. How Bees are attracted to Flowers 



In bees the sense of smell is equally well developed. But 

 no topic in comparative psychology has been more hotly . 

 disputed than the use which bees make of this sense, and the * 

 extent to which they depend, rather, upon sight. Darwin 

 (90) and H. Muller (284, 285) thought both color and 

 fragrance influential in attracting insects. Plateau main- 

 tains that the chief influence attracting bees to flowers is 

 smell, and that color has little effect. He made a number of 

 experiments in which the brightly colored corollas of flowers 

 were cut off without disturbing the nectaries, and claims to 

 have found that the visits of bees to the mutilated flowers 

 were as frequent as before (336-338, 339, 341). On the other 



