ROLE OF SEX IN THE EVOLUTION OF MIND 201 



associated with sex are as a rule among the most complex features of 

 the bod}'. Some animals, to be sure, simply discharge their sex cells 

 into the water, leaving their union to chance, but in the majority of 

 cases, especially in higher forms, there exist elaborate mechanisms to 

 insure the meeting of these cells. Correlated with these structures we 

 find mating instincts which frequently manifest themselves in complex 

 modes of behavior. More acute senses have been evolved in many cases 

 very largely for effecting the meeting of the sexes. The large antenna? 

 of male moths, the large eyes of the common drone bee, and the audi- 

 tory apparatus of the male mosquito are a few of the countless illustra- 

 tions of this fact. The various apparatus in insects for making sounds 

 which are found in crickets, locusts, cicadas, etc., are devices for secur- 

 ing the meeting of the sexes, and the complementary development of 

 the auditory apparatus in the same insects has doubtless been furthered 

 through the evolution of these structures. 



Much of the elaborate organizations of the imago stage of insects has 

 reference, directly or indirectly, to activities concerned in mating and 

 depositing the eggs in the proper environment for the development of 

 the young. There is a relatively long larval or nymphal period chiefly 

 devoted to the vegetative functions of assimilating nutriment and 

 growth ; in many cases the imago takes no food, or need take none, 

 before the eggs are fertilized and laid; and in several species the mouth 

 parts have become so completely atrophied that food taking is impos- 

 sible. Mating not infrequently occurs soon after the insects emerge 

 from the pupal covering. In the may-flies, which live but a short time 

 in the winged state, in order to mate and deposit their eggs it is prob- 

 able that the imago stage would long ago have disappeared were it not 

 retained as a means of effecting the union of the sexes. The same is 

 doubtless true of many other insects. The activities of the imago state, 

 broadly speaking, are primarily altruistic ; they are concerned mainly 

 with the welfare of other members of the species. They are also expen- 

 sive. In the winged state numerous new enemies are encountered and 

 many lives are lost. In the pupa stage which prepares for it there is 

 commonly an extensive tearing down of old structures and the building 

 up of new ones, during which the'insect is helpless against many enemies. 



Mating activities are almost everywhere among the most complex per- 

 formances of an animal's life. The opposite sex must be distinguished 

 from all other creatures and responded to accordingly. Often pursuit and 

 capture or winning over are the necessary preliminaries to sexual union. 

 All this puts a premium, so to speak, on the sharpening of the senses, 

 the development of strength and activity, and the evolution of the 

 higher psychical qualities. Consider the mating activities of crustaceans, 

 the courtship of spiders, the breeding habits of fishes, and still more 

 the elaborate wooing of male birds, and it will become manifest how 



VOL. LXXXV. — 14. 



