2io PROBLEMS OF GENETICS 



Ragusa for a whole summer in very damp conditions. Neither is 

 Kammerer's theory in accordance with the distribution of the 

 black lizards, as pointed out by Werner. Kammerer also finds 

 that those forms which are known to produce melanic races in a 

 state of nature, lend themselves more readily than the others 

 to the success of his experiments. But he shows himself misin- 

 formed when he states that the variety called Lacerta fiumana 

 belongs to the category of those of which black forms are not 

 known. He overlooks the fact, first pointed out by Scherer in 

 1904, and which I can confirm, that the black lizard from Meli- 

 sello near Lissa in the Adriatic is unquestionably derived from 

 the lizard from Lissa, which he correctly regards as not separable 

 from L. fiumana. . . ." 



" Another colour modification which Dr. Kammerer states 

 that he obtained by raising the temperature is the assumption by 

 the female of the typical Lacerta muralis of the bright red colour 

 of the lower parts which often distinguishes the male from the 

 female, and which was not shown by the individuals of the latter 

 sex kept by him under normal conditions. He quotes various 

 authorities to show that the lower parts are never red in the 

 females, but he has omitted to consult others who say the con- 

 trary. Thus Bedriaga (1878 and 1879) remarks that a so-called 

 var. rubriventris of the typical wall lizard has the lower parts red 

 in both sexes." 29 



In reading such papers as those of Semon or Kammerer the 

 thought uppermost in my mind is that to. multiply illustrations 

 of supposed transmission of acquired characters is of little use 

 until some one example has been thoroughly investigated. If 

 we had certain assurance that even a single unimpeachable case 

 could be repeated at will, the whole matter would assume a more 

 serious aspect. If, for instance, Kammerer were able to show us 

 Alytes males with horny pads on their hands, it would be some- 

 thing tangible; still more, if the experiment were repeated by 

 others until no doubt remained that the offspring of Alytes which 

 had bred in water for some three generations did acquire these 



29 As to the variations of Lacerta muralis in Western Europe and North Africa 

 see Boulenger, G. A., Trans. Zool. Soc., 1905, vol. XVII, p. 351. 



