Fasten , Parthenogenetic Data. 
67 
time, so long as they are not of a sort to interfere very materially 
with the process of assimilation, or to threaten the life of the indi¬ 
vidual. 
C. Insects .—Various groups of insects disclose striking 
examples of parthenogenesis. Perhaps the most interesting cases 
are found among the bees, ants, saw-flies, aphids, and Phylloxera. 
In the bees, ants, and saw-flies, parthenogenetic eggs give rise 
to male individuals only, whereas, females are produced through 
fertilization. Undoubtedly, the cases of the bees and ants are the 
most familiar. Let us consider them more fully. 
(i). Bees and Ants. Five days after pupation, the queen 
bee generally leaves the hive and takes the “nuptial flight,” in 
order to meet the male. Copulation occurs in the air, and the 
sperm become stored in the spermatheca of the female. When 
the ova are mature, they are passed out of the oviducts and are 
fertilized by the spermatozoa stocked in the queen’s receptacle. 
In the case of old females, where the sperm has been all used 
up, and also in cases where the queens have not been fertilized, 
only unfertilized eggs are laid. Thus, two types of eggs are 
produced, those that have been fertilized and those that have not 
received the sperm. 
The queen now deposits the fertilized eggs into the queen 
and worker chambers, while the parthenogenetic eggs she places 
into the drone compartments. From the former, fertile and infer¬ 
tile females arise, whereas, the latter eggs develop into drones. 
In the Ants, the development of the queens, workers and males 
is exactly similar to the Bees. 
Johannes Dzierzon was the first investigator to observe par¬ 
thenogenesis among the bees. He was a careful worker and 
showed that the eggs of the queen, when they come to maturity 
in the ovary, are, from all outward appearances, identical, and that 
their subsequent development into males or females depends 
wholly on the fact of their being fertilized, or their not being fer¬ 
tilized. Based on these observations, in 1845, he announced the 
theory, now classic, that the unfertilized eggs develop into males, 
whereas those that have been fertilized, produce either queens 
(fertile females) or workers (unfertile females). In other words, 
the sex is determined by fertilization. 
