80 Annals Entomological Society of America [Vol. IV, 



4. Potency of Fertilization. 



As concerns this point, it was noticed in the case of the hiber- 

 nated pairs, and with these pairs only was opportunity presented 

 to gather any data bearing on the question, that the female of 

 Pair No. 1 continued to deposit fertile ova for one month after 

 the absence of the male (June 4, 7 p. M., to July 4, 2:50 

 p. M.); and that the female of Pair No. 3 deposited fertile ova 

 for seventeen days after the death of her mate. No other 

 data were obtained. 



5. Number and History of Generations Reared in the Laboratory. 

 Our data here are also meagre, but they certainly do tend to 



uphold the opinion that the adults of the second generation 

 (or parents of the third generation) are at least able, if not 

 willing, to reproduce and hence the observations of last year 

 (Girault 1908) are upheld and Tower's (1906) dictum that 

 "The second generation does not develop the germ-cells nor 

 show any reproductive activity until after it has passed through 

 a period of hibernation or aestivation" becomes in our minds 

 less and less authoritative. These beetles of the second gen- 

 eration with us certainly showed reproductive activity, if 

 repeated matings can be called such, and one pair, even under 

 very adverse conditions — starvation — deposited fertile eggs, 

 which surely must be conceded to be reproduction which cannot 

 of course take place without development of the germ-cells. 

 The beetles with us this year plainly showed symptoms of what 

 we would call eagerness and ability to reproduce. These 1 teetles 

 were those of the second generation, as will be shown in the fol- 

 lowing brief historical sketch, and were normal in every way. 

 that is to say, did not represent any special race of the species. 

 On May 23, 1908, or at the earliest possible date, 00 eggs 

 of the species were collected from a potato plant in a small plot 

 of potatoes at Urbana, Illinois and brought to the laboratory 

 to comprise the first generation or descendants of the hiber- 

 nated adults. The larvae came to maturity early in June and 

 pupated and eleven adults emerged between June 21 and 

 June 23. They were confined together with food. On the 

 latter date a pair were 1 found mating and were at once isolated 

 as the parents of the second generation.* From this pair of 

 adults of the first generation, there were taken for the special 



*The others were accidentally poisoned with arsenate of lead. 



