THE DETERMINATION OF SEX. 105 



of which kind of egg she is about to lay next, and seeks the proper cell 

 to deposit it in. There are, however, some further facts that show 

 that the conditions may be more complicated than has been generally 

 supposed. 



It has been possible to introduce a virgin queen of an Italian stock 

 into a hive containing workers and males of a German stock. These 

 two kinds of bees are sufficiently different to be readily distinguished 

 from each other. The Italian queen becomes fertilized by the Ger- 

 man males. In consequence all the queens and workers that come from 

 her eggs are hybrids, since they come from fertilized eggs, but the males 

 or drones are nearly all of the same kind as the queen, which indicates 

 that they have come from unfertilized eggs. Occasionally, however 

 — and this is the point of special interest in the present connection — 

 a few males appear that are hybrids, as Dzierzon long ago observed. 

 Hence we must suppose that an egg has been fertilized, and despite 

 this fact it has developed into a male. This conclusion may indicate, 

 as Beard has recently claimed, that the sex of the egg must have been 

 already determined, and was not altered by the accidental entrance of 

 a spermatozoon. 



In this connection it should be pointed out that Weismann and 

 Petrunkewitsch found that out of 272 drone eggs that they studied 

 there was one that had been fertilized. Whether it would have become 

 a male or not, could not be determined; for it is said that the queen 

 sometimes makes a mistake and deposits a worker egg in a drone cell. 

 Indeed 'whole combs of drone cells may produce workers instead of 

 drones. ' 



These are some of the principal facts that seem to show that the 

 sex of the individual is predetermined in the Qgg. From the evidence 

 Cuenot arrives at the following general conclusions: He thinks that 

 in the great majority of animals the sex is determined in the egg and 

 at latest when the egg is fertilized. In no instance, he claims; has it 

 been shown that the sex of the individual can be determined later than 

 fertilization. The classic examples, insects and frogs, in which it was 

 supposed that external conditions acting on the later embryo deter- 

 mined the sex, have been shown to be capable of a different interpreta- 

 tion. It has been especially made clear, Cuenot claims, that a meager 

 or an abundant supply of food has no influence on the determination 

 of the sex of the embryo. He believes moreover that it is the egg and 

 not the spermatozoon that determines the sex of the individual. In 

 several insects, in Dinophilus, in pigeons, and in the winter eggs of 

 aphids and of daphnids, this has been clearly shown to be the case. 

 In other animals, as in the rotifers and in the social hymenoptera, the 

 spermatozoon appears to have a determining influence. In the mam- 

 mals the entrance of the spermatozoon may have only the same in- 



