KNJIŽEVNE OBZNANE I RAZLIČITI ČLANCI. 



On colour-change of Salamandra-larvae, 



Slavko Šećerov, D. Ph. Belgrad. 



In answer to Prof. Werner's criticism of my experiments.^) 



The subject of Prof. Werner s criticism are my experiments oii 

 the colour-change in Salamandra-larvae, reared in yellow and black 

 environment, first published in Glas 87 of Royal Serbian Acad. 1912. 

 and then in Biol. Centralblatt, Vol. 34. 1914. (Über das Farbkleid 

 von Feuersalamandern, deren Larven auf gelbem und schwarzem Un- 

 tergrunde gezogen waren). 



By means of these experiments the colour-change of Salamandra- 

 larvae was first positively shown. The larvae of a yellow stripped 

 variety of Salamandra maculosa show colour-adjustment, like that 

 of the metamorphosed animals. 



When reared in a yellow environment or black-ground tili the 

 time of metamorphosis, they become more yellow coloured, then 

 the mother, from which some larvae had been extracted by Opera- 

 tion and some had been born naturally. The spots become larger. 

 The Strips tend to unite on the back. The fingers become more 

 yellow, than those of the mother. 



When reared in a black environment, the number of yellow 

 Spots increases by the Salamandra' but this augmentation is not caused 

 by increase of the yellow colour but because longitudinal strip is 

 broken into spots or because the spots are not united in strip. 



This is proved by the fact that the smaller, yellow mother-spots 

 disappear in the case of the same larvae. 



Prof. Werner's criticism contains several inaccuracies of text 

 and explanation, that I am obliged, though late, to reply. The 

 remarks show, that Prof. Werner is unable to understand experi- 

 mental aims and methods of biological research. 



The criticism beginns with following, apparently well grounded, 

 fundamental adjections : 



i. The number of animals, experimented on, was too small 

 (only \2). 



2. The duration oT experiment was too Short, being only 7 weeks. 



Ad. 1. It is quite right, that the number of animals was not very 

 large, but each of larvae is descended from one mother and of 

 course, I could not increase the number at my Option, at a given 



') Einige Bemerkungen zu den Salamandra-Experimenten von Šećerov 

 und Kammerer von Franz Werner (Wien). Biol. Centralblatt Vol. 35. 

 No. 4. 1915. 



