352 MISSES K. FOOT AND E. C. STBOBELL : RESULTS OF 



the spring they iiicated and deposited eggs quite normally ; 330 eggs being- 

 deposited by the two females before July 9th, when they were killed. It was 

 from these eggs that we raised the variolarius specimens used for the above 

 described unsuccessful cross-breeding experiments with servus. We also 

 tried to breed from several of this first generation of variolarius to use as a 

 control for our cross-breeding experiments, and to test the above described 

 experiment of 1911 with the first generation of that season. We had three 

 cages of these experiments in 1912, including in all 18 females and 13 males. 

 The first cage was started July 15th, and these experiments were not closed 

 until August 29th. During this period only one pair* of these 31 bugs 

 mated (August 16th) though many unfertilized eggs were deposited in the 

 three cages. The fact that in all these experiments unfertilized eggs were 

 deposited, proves that the young females function the same season, but our 

 experiments indicate that the young males rarely function until the next 

 spring. The following experiments bearing on this ])oint may be added to 

 those already given. As stated above, the young pairs of variolarius that 

 were caged in 1911 did not mate, although the females deposited unfertilized 

 eo-o's. Thinking this might be due to the fact that these bugs were all from 

 the same batch of eggs, we caged one of these F^ males with a wild female 

 th;it had just mated with a wdld male. They did not mate, however, although 

 the female continued to deposit eggs at normal intervals until August 22nd, 

 and was not killed until September 26tli. 



In the season of 1912 we were anxious to test this experiment by caging 

 wild males, after they had mated in the laboratory, with young females that 

 were depositing unfertilized eggs, but we did not succeed in capturing any 

 variolarius males that season, though we searched ourselves, and had assistants 

 searching also. 



That ihe young variolarivs males rareh^ function tlie same season in the 

 laboratory was ag an indicated by the following exj)eriment. Five young 

 variolarius males had been caged for five weeks with fiv(; Fj hybrid females, 

 and had not mated once, although the females had de|)Osited ^'S unfertilized 

 eggs. Tliinking that perhaps these males might be sexually immature, they 

 were replaced by the one young variolarius male that had mated in the 

 laboratory that season. Eleven days later this male mated with one of the 

 Fi hybrid females (see Record XI. and p. 345). 



These facts would seem to indicate that the young male variolarius are not 

 as a rule sexually mature the sauie season they are hatched, but the evidence 

 on this point is entirely inadequate as proof. Variolarius females that were 

 depositing unfertilized eggs also failed to mate with the Fi servus males, 

 and these males were undoubtedly sexually mature, for they breed readily 



* This pair was transferred to a separate cage while mating, and used for experiments 

 described below. The male of this pair is shown on Plate 34, photo 58, 



