Makch 4, 1904.] 



SCIENCE. 



391 



That the eggs laid in such cases in worker 

 cells are in reality fertilized) and those laid in 

 drone cells unfertilized, has been established 

 by direct observation. Von Siebold examined 

 under the microscope 40 fresh laid eggs taken 

 from worker cells; in 30 of these he was able 

 to identify one or more spermatozoa; in three 

 eases the spermatozoa were still moving. In 

 24 eggs taken from drone cells and carefully 

 examined, no spermatozoa, were seen. Von 

 Siebold's observations are fully confirmed by 

 results obtained by the more perfect methods 

 of microscopical study now available. Pe- 

 trunkewitsch (1901), who has recently made a 

 careful study of the bee's egg by means of 

 sections, found 61 ripe eggs taken from worker 

 cells to have been fertilized, while in only one 

 such egg he found no evidence of fertiliza- 

 tion; on the other hand, 273 eggs taken from 

 drone cells were all, with one exception, un- 

 fertilized. In this one egg the presence of a 

 spermatozoon was indicated. That egg, how- 

 ever, can hardly rank as an undoubted excep- 

 tion to the perfectly obvious general rule. It 

 may well have come from one of the cells of 

 intermediate size on the border between the 

 drone comb and the worker comb, from wliich 

 either workers or drones may develop, or it 

 may even have been introduced accidentally 

 from worker corab into the lot of eggs in 

 which it was found. 



In favor of the view resurrected by Wheeler, 

 that female bees may develop from unfertil- 

 • ized eggs, not a bit of trustworthy evidence 

 has ever been presented, so far as I know. 

 Certainly Wheeler presents none. The 

 strongest support ever given to such an idea 

 came from the experiments of Landois (1867). 

 He transferred eggs from drone to worker 

 cells and vice versa, and concluded that the 

 sex of the bee produced depends upon the 

 nature of the cell in which it develops, or 

 more directly upon the character and amount 

 of the food supplied to it. But Bessels (1868), 

 who repeated the experiments of Landois, 

 found that the workers regularly destroy eggs 

 transferred from one cell to another, and the 

 queen then lays new eggs in their stead. Ber- 

 lepsch, however, as quoted by Bessels, by first 

 removing the queen from the hive, and then 



by transferring a segment of the cell with the 

 egg attached, succeeded in getting the workers 

 to rear in worker cells a few eggs laid in drone 

 cells. From these developed only drones! 



But in the case of ants, Wheeler thinks it 

 even a ' probability ' that female ants develop 

 from unfertilized eggs, and the title of his 

 article would lead one to suppose this already 

 a demonstrated fact. His conclusion cer- 

 tainly receives no support from the case of 

 the honey-bee. We may accordingly reason- 

 ably ask for pretty clear evidence in its favor 

 from some other source before accepting it 

 as even proiahle. What evidence has Wheeler 

 to present ? Three different cases recorded by 

 competent observers, in which worker ants 

 have produced female offspring. But does it 

 follow, that the eggs from which these off- 

 spring developed were unfertilized? Clearly 

 not. Because worker bees do not mate with 

 drones, it does not follow that worker ants 

 never mate with male ants. Indeed, Wheeler 

 quotes Eeichenbach, whom he characterizes as 

 ' a very conscientious worker,' to the effect 

 that in at least one species of ant, Anergates 

 atratulus, ' fertilization always occurs nor- 

 mally within the nest.' If fertilization may 

 occur within the nest, why may not the wing- 

 less worker mate with a male, as does the 

 winged queen? At any rate, this possibility 

 must first be excluded before we shall be justi- 

 fied in drawing the conclusion that all eggs 

 laid by workers are necessarily unfertilized 

 eggs. It is a possibility which two of the 

 authorities cited by Wheeler, viz. Tanner and 

 Eeichenbach, distinctly recognize. They both 

 emijhasize the fact that the workers which 

 under their observation produced female off- 

 spring ' had been living in community with 

 males.' 



ISTor does the third authority, as cited by 

 Wheeler, Mrs. A. B. Comstock, even suggest 

 that the eggs laid by worker ants in the colony 

 kept by her were unfertilized eggs. The credit 

 for that idea belongs solely to Wheeler. What 

 she records is that worker ants taken from 

 out of doors laid in captivity eggs which de- 

 veloped into females. Is there any reason for 

 supposing that the ants captured had not pre- 

 viously been with males ? If not, then where- 



