THE OSMI^ 265 



therefore know what may have been done in the direc- 

 tion whither this study of the sexes has led me. If I 

 am stating propositions that are really new or at least 

 more comprehensive than the propositions already known, 

 my words will perhaps sound heretical. No matter: as 

 a simple translator of facts, I do not hesitate to make 

 my statement, being- fully persuaded that time will turn 

 my heresy into orthodoxy. I will therefore recapitulate 

 my conclusions. 



Bees lay their eggs in series of first females and then 

 males, when the two sexes are of different sizes and de- 

 mand an unequal quantity of nourishment. When the 

 two sexes are alike in size, as in the case of Latreille's 

 Osmia, the same sequence may occur, but less regularly. 



This dual arrangement disappears when the place 

 chosen for the nest is not large enough to contain the 

 entire laying. We then see broken layings, beginning 

 with females and ending with males. 



The egg, as it issues from the ovary, has not yet a 

 fixed sex. The final impress that produces the sex is 

 given at the moment of laying, or a little before. 



So as to be able to give each larva the amount of space 

 and food that suits it according as it is male or female, 

 the mother can choose the sex of the egg which she is 

 about to lay. To meet the conditions of the building, 

 which is often the work of another or else a natural 

 retreat that admits of little or no alteration, she lays 

 either a male egg or a female egg as she pleases. The 

 distribution of the sexes depends upon herself. Should 



