THE HEDGEHOG'S HOLE. 55 



stage of mammalian life which the other 

 European animals have long passed by. 

 Time was when the ancestors of dogs and 

 deer and sheep and rabbits had risen no 

 higher in the scale of life than these small- 

 brained and stupid little creatures. But 

 while the other races have for ages out- 

 stripped their hedgehog-like ancestors, the 

 hedgehogs themselves have remained always 

 at the same low level of development and 

 intelligence. Such arrests are not uncommon. 

 In the dim past of geological ages, we know 

 that there must have been at some time a 

 primitive forefather of the whole mammalian 

 stock who had some affinities to the true 

 reptiles and still more to the frogs. Of this 

 hypothetical progenitor of hedgehogs and 

 men we have now no trace; but of many 

 subsequent stages we have traces in abund- 

 ance. The ornithorhynchus and echidna, 

 which are mammals only by courtesy, still 

 preserve for us the intermediate step between 

 this frog -like creature and the true quad- 



