112 TYPES OF ANIMAL LIFE 



A little less than twenty years ago, there were a 

 number of axolotls living in the Jardin des Plantes at 

 Paris, under the care of a very intelligent keeper. One 

 day to his astonishment he missed one of his axolotls, 

 but found in its place a very different-looking eft, and 

 one without any gills. A little later the same thing 

 Fig. 31. happened in the case of several 



of them, and thus it became 

 known that the axolotl is but a 

 big and precocioiis baby, ready 

 to change rapidly, under certain 

 conditions, into the form of an 

 amblystoma. This change is a 

 very remarkable one, because 

 it by no means consists merely 

 in the loss of the gills, but 

 involves changes in the bones 

 of the skull, the number and 

 ; arrangement of the teeth, as 

 well as other important struc- 

 tural transformations. The 

 change was the more singular 

 because, although the unchanged 

 ' " axolotls continued to breed 



_' freely in their immature con- 



rdition without any care or 

 trouble to their keeper, none 

 THE AXOLOTL. ^f ^j^g transformed ones could 



be induced by any effort of his to do so. It seemed 

 as if they had, on obtaining maturity, discarded all con- 

 jugal famUy feelings as mere follies of youth. 



This curious change in the axolotl, and its long persist- 

 ence in breeding in a condition which, as far as form 

 and structure go, must be regarded as an immature one, 



