LIFE HISTOKV AND HABITS. 41 



the cokl rooms, contaiiKMl only seniidonnuiit beetles, but alter beinji; 

 placed in the sun for a time the beetles very soon became active and 

 co])ulation took place. When the cages were returned to the cold 

 rooms it was only a few moments until copulation ceased and the 

 beetles became sluggish again. 



The method of mating of these beetles seems to be more or less 

 unic^ue. The male shows no signs of excitement until he comes in 

 contact with the female, and then he rapidly attempts copulation. 

 After the male has assumed his position he throws himself over back- 

 ward so that he is on his back with his body in the same line with 

 tliat of the female, but pointing in the opposite direction. The 

 male then folds his legs and antennae close against his body and 

 remains quiescent during the operation. If disturbed the female 

 seeks shelter, walking slowly and dragging the male after her. The 

 duration of the process varied greatly in the cases noted, covering 

 from 7 to 19 minutes. After the operation the male was generally 

 noted to be much more active than the female, but was not seen to 

 attempt copulation a second time, even where the pair were confined 

 in a small vial for some hours. 



^luch of the copulation attempted in the cages was unsuccessful, 

 about nine attempts out of every ten coming under this head. When- 

 ever several males were attempting copulation with the same female 

 at the same time they were noted to fight one another. 



About April 1, 1912, the abdomens of the females began to swell 

 noticeably and a close watch was kept for the eggs. Every day 

 about six females were dissected so that the development of the eggs 

 could be watched. The immature eggs were small and disk-shaped, 

 being little more than half as large as the mature eggs. They ap- 

 peared as opaque spots in the translucent jellylike ovaries, which 

 filled quite completely the ventral portion of the abdomen. The 

 development of the eggs was relatively slow, the greatest change 

 a})pearing in the ovaries, which increased rapidly in size until at 

 the time of oviposition they practically filled the abdomen. 



ACTIONS OF THE ADULTS AFTER MATING. 



During the last week before oviposition the females spent all their 

 time burrowing under the soil, and were never noted feeding or on 

 the surface. Wlienever they were dug up they immediately buried 

 themselves again. If the ground was not allowed to dry out too 

 much the females remained active and healthy, but in several cells 

 in which the soil completely dried out the females died. 



The males did nothing but feed and crawl about on the surface. 

 They lived, on the average, from two to four weeks after mating, so 

 it seems possible that one male might fertilize more than one female. 



