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SCIENCE. 



[N. S. Vol. XIX. No. 479. 



invariably and would see it replaced with so 

 far as observed, I am quite ready to grant all 

 that he desires. It scarcely requires explicit 

 statement here that all conclusions of induct- 

 ive science must be so qualified. 



But if, as seems possible, Wheeler's objec- 

 tion extends farther and he would have us 

 understand that the generalization made is 

 supported by insufficient or uncritical observa- 

 tion, I would join issue with him sharply. 

 Dzierzon's theory did not grow out of idle 

 speculation, as a casual reading of Wheeler's 

 article might lead one to suppose; it was the 

 outgrowth of much careful observation and 

 thought on the part of a keen-eyed bee-keeper. 

 It won its way to general recognition in the 

 face of bitter opposition and has successfully 

 withstood for half a century repeated assaults 

 from various sources, scientific and otherwise. 

 A brief summary of the evidence on which it 

 rests may not be out of place here. 



1. Dzierzon showed more than fifty years 

 ago* that mating of the queen-bee - (the egg- 

 laying female of the hive) does not take place 

 within the hive, but high up in the air. It 

 takes place, if at all, before the queen has 

 begun to lay eggs, and occurs but once in the 

 lifetime of the queen, viz., in what is called 

 her ' nuptial flight.' For this flight she issues 

 from the hive on a bright still day. Her 

 seminal receptacle then contains only a thin 

 watery fluid, as Dzierzon and his coworker, 

 Berlepsch, found by dissection. When she 

 returns, the seminal receptacle is swollen and 

 opaque, crowded with spermatozoa. This ob- 

 servation we have on the added authority of 

 von Siebold, who made microscopical examina- 

 tion of the seminal receptacle of a queen cap- 

 tured as she returned from the nuptial flight. 



2. If for any reason the queen is unable to 

 take the nuptial flight, as because she has 

 crippled or defective wings, or because her 



* Tlie original papers of Dzierzon were published 

 in a bee journal now not generally accessible, Die 

 Bienenzeitung, but extensive quotations from them 

 are contained in the classical paper of von Sie- 

 bold, ' Wahre Parthenogenesis bei Sehmetterlingen 

 nnd Bienen,' Engelmann, Leipzig, 1856. Other 

 important papers on this subject are those of 

 Bessels (1868), and Petrunkewitsch (1901,1903). 



wings have been artificially removed, she is 

 not prevented thereby from laying eggs ca- 

 pable of development, but from such (imfer- 

 tilized) eggs develop only bees of the male 

 sex (drones). This conclusion, the outcome 

 of repeated observations made by Dzierzon, 

 Berlepsch and Bessels, is further supported by 

 an experiment made by Berlepsch. He in- 

 duced a hive , of his bees to rear queens late 

 in the season (near the end of September), 

 after the drones had disappeared. One of 

 these queens, which was ■ wintered over, pro- 

 duced in the following spring some 1,500 cells 

 of drone brood in worker cells. A dissection 

 of this queen made by Leuckart showed that 

 she really was, as expected, unimpregnated. 



3. Worker bees, which are only imperfectly 

 developed females, sometimes lay eggs capable 

 of development. This frequently occurs after 

 a hive has lost its queen. From such ' worker ' 

 eggs develop only male offspring. Dissections 

 of egg-laying workers, which were made by 

 Leuckart, revealed no seminal receptacle, 

 hence the eggs of such animals can not have 

 been fertilized. 



4. Old queens, which possibly have ex- 

 hausted or lost control of the supply of 

 spermatozoa received at the nuptial flight, 

 sometimes produce only drone offspring (in 

 worker as well as in drone cells). An old but 

 fruitful queen, which had been producing off- 

 spring of both sexes, was accidentally crushed 

 toward the tip of the abdomen by Berlepsch, 

 so seriously that he thought her dead, but she 

 revived after about an hour and was replaced 

 in the hive. All the eggs which she subse- 

 quently produced (and they numbered thou- 

 sands) developed into drones. This case is, 

 with a good show of reason, explained on the 

 hypothesis that the genital organs of the 

 queen were so injured by the accident that 

 thereafter none of her eggs could be fertilized. 



5. Queens which have mated in normal 

 fashion subsequently lay eggs some of which 

 are fertilized, others unfertilized. The fer- 

 tilized eggs are deposited ordinarily only in 

 the small worker cells or the very large queen 

 cells, and they develop into females. The 

 unfertilized eggs are deposited ordinarily only 

 in the drone cells, and they develop into males. 



