METAZOA INSECTA. 481 



tion and called workers) are old enough to assume the 

 responsibility of carrying on the industrial work of the 

 nest and of providing in their turn for their mother. She 

 then gives up the many activities in which she has been 

 engaged and devotes herself wholly to one object, that of 

 increasing the size of the family which now may be called 

 a colony. In this colony there are, besides herself who 

 is now the queen, males and workers. The males take 

 no part whatever in the industrial employments of the 

 nest and are apparently unaware of them (Sharp). 

 There is no distinct line of demarcation between the 

 worker and queen, such as we shall find farther on in the 

 social bees, although the development of the reproductive 

 organs of the worker has been in a measure suppressed. 



The larva of most of the social wasps is a colorless, 

 legless grub which lies head downward in the cell of the 

 nest. It is held in this position when young by a sticky 

 secretion ; later the enlarged anterior end of the body 

 just fits the opening and holds the insect in place. It is 

 fed on prepared food, but the pupa stage is quickly 

 reached and soon passed, and the adult (No. 1228, Polis- 

 tes metricus Say) comes forth armed and equipped for 

 work. It makes its nest (No. 1229) which consists of a 

 single layer of cells without an external covering. The 

 material of the nest is obtained by scraping weather- 

 beaten wood with the mandibles, chewing it, and mixing it 

 with the saliva. In each cell an egg is laid and when the 

 young are hatched they are fed by the females and workers 

 on the sweet juices of flowers and fruits besides some 

 well masticated solid food. 



One of the most social wasps is Vcspa metadata Linn. 

 (No. 1230, larva; No. 1231, $ ; No. 1232, 9 ; No. 

 I2 33? ? ) I ts papery nest (No. 1234) is made of rows of 

 cells, one placed below the other, and protected by a 

 thick outer covering. These nests vary in size, a large 

 one in my possession measuring forty-two by fifty-one 

 inches in circumference. These nests are used only one 



