INHERITANCE OF PARENTAL MODIFICATIONS 77 



worker-bees have been developed through natural selection, 

 I would suggest that the argument stated above is hardly 

 conclusive. The sterility of the worker-bees is a character 

 acquired within comparatively recent times. Their compli- 

 cated instincts (or high degree of intelligence) may have 

 been acquired before they became sterile. This possibility 

 is suggested by the fact that the fertile females of certain 

 wasps have most remarkable instincts, almost, if not fully, 

 as wonderful as those of the worker-bees. Among the 

 solitary wasps the fertile females never cease to exercise 

 their special instincts. Among some of the social wasps, 

 on the other hand, we find species in which the fertile 

 females exercise these instincts for a time and later cease 

 to use them. Dr. and Mrs. Peckham say of the genera 

 Vespa and Polistes : " In the autumn the queens, having 

 mated with the drones, creep away into crevices and shel- 

 tered corners, where they pass the winter. In the spring 

 they may be seen seeking for suitable nesting places, and 

 forming, from the fibres of weather-beaten wood, which are 

 scraped off and chewed up, the first layer of cells. So 

 much being accomplished, the queen deposits her eggs, one 

 in each cell, and when these develop into grubs she feeds 

 them, until at the end of a week or ten days they spin their 

 cocoons and become pupae. In from eight to ten days the 

 perfect wasp is formed and emerges from its cell ready to 

 assume its share of responsibility in the work of the nest. 

 These first wasps are always neuters, and hereafter all the 

 duties which the queen has been obliged to perform, with the 

 single exception of egg-laying, fall upon them." The neuters 

 of these social wasps die when winter comes on. Should 

 they live through the winter, there would be no need of the 



