» LIFE HISTORY AND HABITS OF POLISTES METRICUS 281 



each trip afield, whether for food or wood pulp, she would 

 tarry for a minute or two to clean herself carefully from any 

 clinging dust and be off again. As the season advanced the 

 number of larva? increased and made a corresponding demand 

 upon their mother for food. By the middle of July several 

 had spun their cocoons, but more eggs were being laid in the 

 newly built cells and other eggs were hatching. 



On the morning of the 16th of July the nest was visited 

 as usual. There had been a heavy rain lasting through most 

 of the night before. The nest was dislodged and had fallen 

 to the ground and the mother wasp was nowhere to be seen. 

 The nest was carefully replaced and fastened to the board 

 with glue and pins. After waiting all day for the return of 

 the mother it became apparent that she was lost. I could 

 ill afford to lose the wasp family at this stage of the observa- 

 tion, for eggs, larva? and pupae were marked to ascertain 

 the period of development. Near at hand was another similar 

 nest, but the mother was not a lively individual, and the nest 

 Avas composed of but a few cells. The nest containing the 

 motherless family was fastened close beside her own to as- 

 certain whether she would adopt the unfortunates. 



The foster mother did not take kindly to such an arrange- 

 ment and moved rapidly over the strange comb, flitting her 

 wings violently, and showing marked evidence of displeas- 

 ure. Since she had seldom been visited I felt that possibly my 

 presence was responsible for her agitation, and accordingly 

 she was left alone until the following morning in order to 

 give her an opportunity to become accustomed to the unusual 

 condition. On my return the next day she bad her head in 

 a cell and backed out with an egg in her mandibles which 

 sli.' proceeded to eat. An examination showed that she 

 had disposed of some of the larva in similar manner. Since I 

 could ill afford to have the observation terminated in such a 

 cannibalistic manner, the nest was taken to the study to see 

 what could be done toward raising the youngsters by hand. 



I soon realized that I had undertaken a rather novel experi- 

 ment. There were eggs which would hatch every day or two 

 for three weeks, young larva 1 just hatched and others in 

 every stage of growth. There were also a considerable num- 

 ber of sealed cells, but as yet none of the pupa- had emerged. 

 I began to frequent the cabbage patch in search of small 



