Photo by Mr. J. G. Hubbaid ami Dr. U. S. Slr^nig 

 WORKERS AND COCOONS OF THE ANT WHICH PASTURES AND GUARDS PLANT-LICE : 



Lasius (Acanthomyops) claviger (sEE text, pages 735, 736) 



This is a common herder of root-lice in the northern States. From the small cocoons 

 males and workers will hatch ; from the two large ones queens. The pale individuals at a 

 are just-hatched callows. Magnification about two diameters. 



should be most diligently discussing eu- 

 genics, or the restriction of reproduction 

 to the sane in mind and body, at a time 

 when we are also most exercised by the 

 high cost of living. Did space permit, it 

 could be shown that man, like other social 

 organisms, has for ages sought and is still 

 seeking means of regulating the repro- 

 ductivity of his race to prevent its ex- 

 ceeding its food supply, and that the ex- 

 pedients on which he has relied in the 

 past, such as monasticism, wars, and the 

 adoption of religious, property, and caste 

 restrictions to marriage, have been only 

 partially successful. 



In termites, both sexes, as we have 

 seen, cooperate equally in the activities of 



the colony, so that each nest contains, be- 

 sides a king and queen, a host of work- 

 ers and soldiers of both sexes. The 

 colonies of ants and the other social Hy- 

 menoptera, however, are essentially femi- 

 nine, since they contain one or more 

 queens and a great number of workers, 

 which are all sterile females, and only at 

 certain times of the year contain any 

 males. These, moreover, take no part in 

 the colonial activities, but live only to 

 mate with the queens of other colonies 

 during the annual marriage flight. 



We are therefore prepared to find that 

 maternity is the pivotal instinct about 

 which all the activities of the ant colony 

 revolve. Not only the queen, the repro- 



743 



