Parthenogenesis in Other Insects. 75 



noticed on any summer day all about us, even on the house- 

 plants at our very windows, that parthenogenesis is best illus- 

 trated by the aphides, or plant lice. In the fall males and 

 females appear which mate, when the females lay eggs whick 

 in the spring produce only females ; these again produce only 

 females, and tiius on for several generations, till with the cold 

 of autumn come again the males and females. Bonnet ob- 

 served seven successive generations of productive virgins. 

 Duval noted nine generations in seven months, while Kyber 

 observed production exclusively by parthenogenesis in a heated 

 room for four years. So, we see that this strange and almost 

 incredible method of increase is not rare in the great insect 

 world. 



About two days after she is impregnated, the queen, under 

 normal circumstances, commences to lay, usually worker-eggs, 

 and if the condition of the hive impels to no further swarming 

 that season, no dronesv wUl be required and so only worker- 

 eggs will be laid. In many localities and in certain favorable 

 years ia all localities, however, further swarming will occur. 



It is frequently noticed that the young queen at first lays 



auite a number of drone-eggs. Queen-breeders often observe 

 lis in their nuclei. This continues for only a few days. 

 This does not seem strange. The act of forcing the sperm-cells 

 from the spermatheca is muscular and voluntary, and that 

 these muscles should not always act promptly at first, is not 

 strange, nor is it unprecedented. Mr. Wagner suggested that 

 the size of the cell determined the sex, as in the small cells 

 the pressure on the abdomen forced the fluid from the sperma- 

 theca. Mr. Quinby also favored this view. I greatly ques- 

 tion this theory. All observing apiarists have known eggs to 

 be laid in worker-cells, ere the cell was hardly commenced, 

 when there could be no pressure. In case of queen-cells, too, 

 if the queen does lay the eggs — as I believe — these would be 

 unimpregnated, as the cell is very large. I know the queen 

 sometimes passes from drone to worker-cells very abruptly 

 while laying, as I have witnessed such a procedure — ^the same 

 that so greatly rejoiced the late Baron of Berlepsch, after 

 weary hours of watching — ^but that she can thus control at the 

 instant this process of adding or withholding the sperm-cells 

 certainly seems not so strange as that the spermatheca, hardly 

 loigger than a pin-head, could supply these cells for months, yes, 



