238 



also facilitate the decay of the log by their activities. There is an 

 "orderly sequence" of changes in the developing colony, and a simi- 

 lar orderly sequence of changes in the log habitat. 



An ant colony in its development clearly illustrates the transfor- 

 mation from the individual to the associational phase of ecological 

 relations. Beginning with the fertilized female and her progeny, 

 the colony develops in size and in the division of labor among its 

 members; until, finally, by the possible addition of slaves, commen- 

 sals, parasites, and even predaceous enemies, the colony or associa- 

 tion is built up in an orderly sequence, and the organisms adjust 

 themselves to one another and to the environment in general. 



MXITILLIDM 



Spharophthalma sp. Velvet Ant. 



This stinging, wingless velvet ant was taken at the margin of the 

 forest near the cleared area (Sta. IV, a) Aug. 23 (No. 151). 



PSAMMOCHAEIDiE 



Psammo chares cethiops Cress. (Pompilus Fabr.j 



This large black wasp was taken by T. L. Hankinson July 10, 

 191 1, in the Bates woods (No. 7693). It probably stores its nest 

 with spiders. 



SPHECIDa; 



Ammophila abbreviata Fabr. Short Caterpillar Wasp. 



This wasp was taken on the open ravine slope (Sta. IV, b) Aug. 

 22 (No. 124). One example (No. 127) was running on the ground 

 in the upland forest ( Sta. IV, a) with a quiescent bombycine cater- 

 pillar — probably Heterocampa guttizntta Walk. — in its grip. 



I took this species of wasp at Bloomington, 111., July 26. Its 

 copulating habits have been recorded, with figures, by Turner ('02). 



