ADAPTATION 199 



that the loss of toes in the offspring may have been due to mu- 

 tilation by the mother, following his experience in a case in which 

 the tails of mice in succeeding litters were thus devoured, and 

 there can be little doubt that in this suggestion lies the clue to 

 the explanation of the whole mystery. Graham Brown concludes 

 that it may be supposed with every degree of probability that 

 the " transmission " was due to injuries inflicted upon the young 

 by their parents. With this conclusion most people will now be 

 disposed to agree, and we may hope that we shall hear the last 

 of this curious myth — to the elucidation of which a vast quan- 

 tity of research has been devoted. 



The series of experiments made by Kammerer with various 

 Amphibia have attracted much attention and have been ac- 

 claimed by Semon and other believers in the transmission of 

 acquired characters as giving proof of the truth of their views. 

 With respect to these observations the chief comment to be made 

 is that they are as yet unconfirmed. Many of the results that 

 are described, it is scarcely necessary to say, will strike most 

 readers as very improbable; but coming from a man of Dr. 

 Kammerer's wide experience, and accepted as they are by Dr. 

 Przibram, under whose auspices the work was done in the Bi- 

 ologische Versuchsanstalt at Vienna, the published accounts are 

 worthy of the most respectful attention. 



The evidence relates chiefly to three distinct groups of oc- 

 currences : 



1. Modification in Alytes obstetricans, the Midwife Toad, 

 affecting both the structure and the mode of reproduction, in- 

 duced by compulsory change of habits. 



2. Modification in the mode of reproduction of Salamandra 

 atra and maculosa induced by compulsory change of habits. 



3. Modification in the colour of Salamandra maculosa induced 

 by change in the colour of the soil on which the animals were kept. 



1. I will take first the case of Alytes, 12 because it is the most 



12 Kammerer's chief paper on this subject is in Arch. f. Entwm., 1909, XXVIII, 

 p. 447, and it is to this that the paginal references in the present text relate. His 

 previous paper appeared, ibid., 1906, XXII, p. 48. An account of his further ex- 

 periments with Alytes is given in Natur, 1909-10, Heft 6, p. 95. 



