Agamic Reproduction in Other Insects, 55 



acterize the cynips or gall-flies; while the great Bonnet 

 first discovered what may be noticed on any summer day 

 all about us, even on the house plants at our very windows 

 that parthenogenesis is best illustrated by the aphides, or 

 plant-lice. In the fall males and females appear which 

 mate, when the females lay eggs which in the spring pro- 

 duce only females; these again produce only females, and 

 thus on for several generations, sometimes fifteen or twenty, 

 till with the cold of autumn come again the males and 

 females. Any person can easily demonstrate this fact for 

 himself. The summer plant-lice are hatched within the 

 mother louse, or are ovoviviporous. It is easy to capture 

 a young louse just as it is born, and isolate it on a plant, 

 when soon we shall find it giving birth to young lice, though 

 it has never even seen any louse, male or female, since birth. 

 Bonnet observed seven successive generations of productive 

 virgins. Duval noted nine generations in seven months, 

 while Kyber observed production exclusively by partheno- 

 genesis 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. 



In two or three days after she is impegnated, the queen, 

 under normal circumstances, commences to lay, iisually 

 worker-eggs, and if the condition of the hive impels to no 

 further swarming that season, no drones will be required 

 and so only worker-eggs will be laid. In many localities 

 and in certain favorable years in all localities, however, 

 further swarming will occur. 



It is frequently noticed that the young queen at first 

 lays quite a number of drone-eggs. Queen-breeders often 

 observe this in their nuclei. This continues for only a few 

 days. This does not seem strange. The act of freeing 

 the sperm-cells from the spermatheca is muscular and vol- 

 untary, 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 spermatheca. Mr. Quinby also 

 favored this view. I greatly question this theory. All 

 observing apiarists have known eggs to be laid in worker- 



