DETLEFSEN 



Photograph^ of AIaj^h SKUi-LS l^■ i'ARiiNi bPECibS AiNu Hvbrh^.s. 



10. r?*/, original wild male ancestor of all 12. S'lO, one-half wild hybrid. 



wild and hybrid animals in 13. J^/J/, one-quarter wild hybrid. 



these experiments. ^^ ^^06, one-eighth wild hybrid. 

 U. c5<?(5, male guinea-pig. 



NOTE. These and all other productions of skulls and bones are natural size, and as near the calculated 

 averages as possible. 



