474 STEFAN KOPEC 



coloring of the insect wing. The results of my experiments on 

 the transplantation of the wing-germs confirm the latter conclu- 

 sion, showing at the same time the principle in virtue of which 

 these animals have quite a different position in regard to the 

 development of their dimorphic secondary characters from that 

 of vertebrates. Steche ('12, a, b) and Geyer ('13), who relied 

 on their experiments on the dimorphic differences of the insect 

 blood, expressed the opinion that the fundamentally different 

 behavior of insects and vertebrates after castration is caused by 

 the fact that the whole body (soma) of the former undergoes 

 sexually dimorphic differentiation from the beginning of life. 

 In the light of my own experiments described in this paper this 

 hypothesis gains a new and important confirmation. 



SUMMARY 



The germ of the imaginal wings grafted on specimens of cater- 

 pillars of Lymantria dispar L. of the opposite sex continues de- 

 veloping, and the differentiated wings have the dimorphic hue 

 proper to them, and not to the specimen on which they develop. 

 The pigments of the scale therefore do not proceed directly from 

 the desiccated blood, but are the product of certain chemical 

 changes which, according to Mayer, occur in the blood under 

 the influence of specific substances contained in the scale-forming 

 cells. 



BIBLIOGRAPHY 



Crampton, H. E. 1900 An experimental study upon Lepidoptera. Arch. f. 



Entw. Mech., Bd.9. 

 Dewitz, J. 1909 Die wasserstoffsuperoxydzersetzende Fahigkeit der mann- 



lichen und weiblichen Schmetterlingspuppen. Zentrbl. f. Physiol,, 



Bd. 22. 



1912 Untersuchungen liber Geschlechtsunterschiede. II. Ibidem, 



Bd. 26. 



1916 a Idem., III. Zool. Anz., Bd. 47. 



1916 b Idem., IV. Zool. Jahrb., Abt . f . allg. Zool. und Physiol., Bd. 36. 

 Geyer, K. 1913 Untersuchungen liber die chemiche Zusammensetzung der 



Insectenliaemolymphe und ihre Bedeutung fiir die geschlechtliche 



Differenzierung. Zeitschr. f. wiss. Zool., Bd. 105. 

 Kellogg, V. L. 1904 Influence of the primary reproductive organs on the 



secondary sexual characters. Jour. Exp. Zool., vol. 1. 



