No. 6. DEPARTMENT OF AGRICULTURE. 689 



mains unfertilized, as do all the eggs of a drone layer. A normally 

 mated queen rarely lays a drone egg in a worker cell, or vice versa. 

 provided both kinds of cells are present, and consequently we are 

 forced to the conclusion, as much as we dislike to admit it, that the 

 queen in some way can control the laying of eggs of different sex. 

 but how this is done is a mystery. I say we dislike to admit this 

 because it is entirely beyond our comprehension and as stated in 

 the earlier part of this talk, one of the difficulties in recording obser- 

 vation is the giving of reasons for things observed. 



Another fact which supports the theory of parthenogenesis is that 

 workers in a colony which is hopelessly queenless will often begin 

 to lay eggs. As we have said, workers as. well as queens are fe- 

 males, but they are incapable of mating, and the eggs laid by them 

 produce nothing but drones. 



This statement of the theory of parthenogenesis or the "Theory 

 of Dzierzon," as it is commonly called, differs from the usual state- 

 ments of the theory that find place in the books on apiculture. The 

 Theory of Dzierzon can be divided into two parts. (1) Drone eggs 

 are unfertilized while female eggs are fertilized. To this part all 

 observations lead us to subscribe. (2) All the eggs in the ovary of 

 the queen are male eggs and the fertilization of the egg changes 

 its sex and it becomes female. 



The latter portion of the theory is not founded on actual obser- 

 vation but on logic only, and not on sound logic either. Let us 

 state the theory in a different manner. Male eggs are unfertilized 

 and female eggs are fertilized. As far as we can see this is the only 

 difference between them, and since we can see no other difference 

 this must be the thing which changes the sex. Is it not clear that 

 the conclusion does not necessarily follow, for is it not possible that 

 there is some difference between these eggs not yet observed, which 

 is the all-determining factor, rather than that fertilization is? 



Fertilization may have nothing to do with sex-determination: 

 (1) Nowhere else is the animal kingdom, except in animals exhib- 

 iting parthenogenesis, is it claimed that fertilization has any in- 

 fluence on sex. (2) The ants, which were formerly considered to 

 be similar to the bee in their parthenogenesis, sometimes, according 

 to some recent work, have females produced from unfertilized eggs. 

 (3) In the vast majority of cases where the problem of sex has been 

 investigated there is strong evidence that the sex of the offspring 

 is determined before the egg leaves the ovary. (4) Certain observa- 

 tions made during the past two summers tend to show that there 

 is some other difference between male and female eggs. 



In studying the problem of parthenogenesis I was struck by the 

 illogical conclusion concerning sex, and to test the theory spent some 

 considerable time in observations on the subject. I found that 

 many of the eggs laid by a drone-laying queen never develop at all. 

 ^According to the theory as propounded by Dzierzon and his fol- 

 lowers, all the eggs in the ovary are male and if they are unfertil- 

 ized all should develop and become drones. But all do not develop. 

 I have observed drone-laying queens in one-frame observation hives, 

 and in eight-frame hives, and in all my observations there were 

 always a considerable number of eggs which dried up and did not 

 develop. Of course, all that did develop became drones. 

 44—6—1905 



