STUDIES IN THE THEORY OF DESCENT. 



ON THE FINAL CAUSES OF 

 TRANSFORMATION. 



in. 



THE TRANSFORMATION OF THE MEXICAN AXOLOTL 

 INTO AMBLYSTOMA. 



INTRODUCTION. 



SINCE the time when Dume>il made known the 

 transformation of a number of Axolotls into the 

 so-called Amblystoma form, this Mexican Amphi- 

 bian has been bred in many European aquaria, 

 chiefly with the view to establish the conditions 

 under which this transformation occurred, so as to 

 be enabled to draw further conclusions as to the 

 true causes of this exceptional and enigmatical 

 metamorphosis. 



Although the Amphibians propagated freely, 

 the cases in which transformation occurred re- 

 mained extremely rare, and it was not once 



O o 



