22O Studies In Animal Behavior 



and even individuals, in higher forms at least, have 

 an odor peculiarly their own which a bloodhound is 

 able to distinguish from among dozens of others. 

 Differences in odor frequently characterize the two 

 sexes, and hence afford a feasible means of sex dis- 

 crimination. 



The males of many forms have much more highly 

 developed olfactory organs than the females. The 

 antennae of insects which contain the olfactory sense 

 organs are frequently larger and more complex in 

 the males. In the drone bee, for instance, the olfac- 

 tory pits of the antennae are many times more numer- 

 ous than in the queen or worker. Many male moths 

 have large feathered antennae, whereas these organs 

 are much smaller in the females. It is mainly 

 through the sense of smell that the male moths are 

 able to find their mates, and in some species this 

 sense is developed to a degree that almost surpasses 

 credence. 



In one of his most delightful essays the French 

 naturalist Fabre tells of the nuptial flight of the 

 males of the large and beautifully colored moth 

 called the great peacock (le grand paon) . A cocoon 

 which was kept in Fabre's study had produced a 

 female moth which was placed under a gauze cover. 

 In the evening the observer had his attention at- 

 tracted by the call of his young son: " 'Come quick, 

 come and see these butterflies ! Big as birds ! The 

 room is full of them!' Several of the large moths 

 had come into the room through the open window. 



