93 



The young one, in fig. 3, reared in blaci< environnment is de- 

 velopped more strong, than the young one in fig. 4, reared in yellow 

 colour and nevertheless the young one in fig. 4, is coioured more 

 yellow than the young one in fig. 3. Is caused by hunger, then the 

 young one in fig, 4, would be also darker, for it is smaller. 



As the animals were drawn in nature-seize (the Originals are 

 at Biolog. Versuchsanstalt), I measured the length of the figures 

 and found, that the dark young Salamandra, reared in yellow envi- 

 ronement and therefore yellow coioured (fig. 4,) has a length of 

 34 mm.; wheras the young one, at the beginning bright, reared in 

 black environement and therefore dark coioured, with few yellow 

 spots, has a length of 36,5 mm. and the Salamandra that was first 

 dark, reared in black environment and blackest, has a length of 

 31,5 mm. 



This number proves clearest that the hypothesis Werner's is 

 incorrect. According to this hypoihesis the dark Salamandra's be- 

 come smaller by hunger, and therefore dark coioured but according 

 to the facts, the asserted smalines in not limited only to the dark 

 individuals, but is shared by the young one, reared in yellow envi- 

 ronnment, small and nevertheless more yellow coioured. 



The cause of the difference of length probably lies in the 

 circumstance that the larvae were obtained by two different methods 

 by Operation and natural birth. It is very propable, that these cir- 

 cumstances caused the difference in development ond seize. 



I might still State, that the animals were therefore not photo- 

 graphed, because the drawing were coioured in the original serbian 

 treatise (Serb. Roy. Acad. Glas 87.) but in Biol. Centralblat the 

 yellow spots were represented as white. Prof. Werner speaks as if 

 I had avoided the photography, but he knows perhaps, that all my 

 measurements on penetration-coeffiecent (Die Umwelt des Keim- 

 plasmas 2. Der Lichtgenuss in Salamandra-körper, then 4. Der Licht- 

 genuss im Lacerta kröper, — Arch. für Entwicklungsmechanik 

 (Roux), V. 33 and 34. 1912.) were made by means of photography. 



Comparing Prof. Werner criticism with the facts my concluding 

 remarks are : ' ■> 



1. The small number of individuals, experimented on, was caused 

 by the circumstance, that all the larvae were obtained from one 

 mother; the number could not be arbitrary increased but therefore 

 the number of experimental factors, specially of the heredity, was 

 diminished 



The objection loses its vaKie totally when we know that 

 the same experiments were continued and confirmed. 



2. The objection that the experimental lasted too short, is 

 without value, because the aim of the experiment. was to influence 

 the colouring of Salamandra's, during the larval period and the 

 experiment lasted, until the larvae, finished this period. Prof. Werner 

 did not understand the aim of experiment. 



3. Prof. Werner supposes, that I say nothing about the initial 

 stage of colouring by the larvae, which can be disproved by accu- 

 rate reading of my treatise (p. 34^). 



