The determination of sex in animal development. 725 



of too great an intelligent power in the bee, and one elsewhere denied, 

 even unto the highest animals. How can the queen-bee know whether 

 or not a certain egg should be fertilised? If she can exercise this 

 power at will, her embryological knowledge is truly remarkable, and 

 probably for thousands of years it has been far in advance of that of 

 mankind ! 



The two statements given above may be put in rather different 

 ways. 1) The eggs, which produce females, are fertilised. 2) The eggs, 

 which give rise to males, are as a rule not fertilised. 



While it is generally true, that the eggs of drone-cells are not 

 fertilised, it is not universally so. The eggs of drone-cells, the 

 male eggs , are sometimes capable of fertilisation , and they are 

 not infrequently fertilised. This, however, does not influence their 

 sex. From the zoological literature dealing with the bee, quite apart 

 from apicultural writings not at the writer's disposal, there is abundant 

 evidence of the truth of this. Weismann records (p. 495), that in 

 272 drone-eggs, sectioned and studied by himself and Petrunkewitsch, 

 there was one fertilised ^). Regarding this instance he says : "with 

 this egg the queen must have 'erred', and by mistake fertilised an 

 egg, although it was laid in a drone-cell. Such an error has indeed 

 long been recognised by apiarists as possible and as happening." 



In the latter sentence he doubtless refers to the well-known fact, 

 that sometimes a queen-bee may make no distinctions as to the cells 

 in which she lays, whole combs of drone-cells may produce workers 

 instead of drones. 



As the experiments of Bessels^) prove, the like results can under 

 proper conditions be produced experimentally, that is to say, a queen- 

 bee can be induced to lay drone-eggs, which invariably give rise to 

 males, in worker- and even in queen-cells, or worker-eggs (female- 

 eggs) in drone-cells without alteration of their prospective destinies. 

 In Bessels' experiments the queen-bee, even when provided with a 

 spermatheca filled with sperms, never "erred" by neglecting to fertilise 

 the eggs, which by the conditions of the experiments she was compelled 



1) He also mentions (p. 494), that in the earlier observations of 

 Paulcke in 3 cases of freshly laid drone-eggs it could not be de- 

 cided whether certain dark bodies should not be identified as sperm- 

 nuclei. 



2) Bessels, Emil, Die LANDois'sche Theorie widerlegt durch das 

 Experiment, in: Z. wiss. ZooL, V. 18, 1867, p. 124 — 141. 



