588 



SCIENCE. 



[N. S. Vol. XIX. No. 



and physiologists. That this is still the case 

 is shown by von Buttel-Reepen's renewed de- 

 fense of the theory within the past two 

 months, that is, since my paper was published.* 

 Of coui'se, such opposition by no means proves 

 that the theory is false, but it shows very clearly, 

 nevertheless, that the phenomena to be ex- 

 plained must be extremely complicated and 

 difficult of observation. And no one who 

 has studied bees or other social insects can 

 doubt the truth of this statement for a mo- 

 ment. Our knowledge of many of the honey- 

 bee's habits, so unique among animals, is 

 based on inferences often very remote and 

 derived from conditions difficult to control; 

 and hence, from a strictly scientific stand- 

 point, more or less insecure. It is impossible 

 to observe these or any other social insects 

 without a sense of powerlessness to ascertain 

 just what is taking place in the life of the 

 colony. We see the insects feeding and rear- 

 ing their broods and regulating the number 

 and character of the personnel of their 

 colonies with a sure instinct analogous to 

 the regenerative and regulatory phenomena 

 manifested by the tissues of the individual 

 organism, but all this takes place as if it were 

 behind a veil. When we are still so pro- 

 foundly ignorant of the exact way in which 

 these wonderful creatures bring about the 

 differences between the queen and the worker, 

 that is, between two forms of the same sex, 

 is it at all likely that we can pose as knowing 

 how the sexes themselves are differentiated? 

 And even if we accept the Dzierzon theory for 

 the bees, are we justified in transferring it to 

 other insects of which our knowledge is still 

 less satisfactory? Even so confirmed an 

 advocate of the Dzierzon theory as von Buttel- 

 Eeepen regards such an extension as inadmis- 

 sible at the present time.f 



Leuckart long ago stated that complete 

 proof of the Dzierzon theory would be forth- 

 coming only when we should have an accurate 



* ' Entstehen die Drohnen aus befruohteten 

 Eiern?' Bicnenu-irthschaft. Gentralhl., No. 3, 

 fF., 1904, 28 pp. 



t ' Die stammesgesehichtliche Entstehung des 

 Bienenstaates,' etc., Leipzig, Georg Thieme, 1903, 

 pp. xii, 1-138, 20 figs. 



knowledge of the bee's egg. There are some, 

 like Castle and von Buttel-Eeepen, who be- 

 lieve that this knowledge has been supplied 

 by the recent Freiburg researches carried out 

 by Petrunliewitseh.* Knowing from experi- 

 ence the extreme difficulty of interpretation 

 and the possibilities of error involved in a 

 study of the polar bodies of the insect egg, I 

 venture to dissent from this view and to re- 

 gard the knowledge to which Leuckart referred 

 as still in the lap of the gods. In support of 

 this statement, I may briefly discuss one as- 

 pect of Petrunkewitsch's work, his contention 

 that the reproductive organs of the drone de- 

 velop from the second polar body of the egg. 

 This fantastical conception, for which not a 

 particle of evidence had ever been furnished 

 by any animal, was suggested as a laboratory 

 hypothesis by Weismann ' mit aller Reserve ' 

 to Petrunlvewitsch while the latter was still 

 working on his dissertation. The suggestion 

 bore fruit in the ' Habilitationsschrift ' as a 

 truly miraculous example of Weismann's 

 powers of prophesy. But to any one who is 

 at all familiar with the developmental stages 

 under discussion, Petrunkewitsch's figures sug- 

 gest anything but what he attempts to prove. 

 Even in his first paper there is no satisfactory 

 evidence to show that the cells regarded as 

 derivatives of the polar bodies in the figures 

 on plate 4 are really such, and not dividing 

 cleavage cells or possibly vitellophags. These 

 stages are all separated by a great gap from 

 those represented on plate 3. When we take 

 up the second paper we wonder how anybody 

 could regard the figures there presented as 

 even an adumbration of proof that the testes 

 of the drone are developed from the polar 

 bodies. There is, in fact, every reason to sup- 

 pose that what Petrunl^ewitsch calls ' Zellen, 

 aus dem Richtungscopulationskern entstand- 

 en ' in his Pigs. 1, 2 and 3, are vitellophags 

 with altered nuclei, such as are often seen in 



* ' Die Rlchtungskijrper xind ihr Schicksal im 

 befruehteten und unbefruchteten Bienenei,' In- 

 auguraldissertation, Zool. JaJirb. Abth. f. Anat. u. 

 Ont., 14. Bd., 4. Heft, 1901; 'Das Schicksal der 

 Riehtungskorper im Drohnenei.' Habilitations- 

 schrift., Zool. Jahrb. Abth. f. Anat. u. Ont., 17. 

 Bd., 3. Heft, 1902. 



