LECTURE XIV. 411 



foundland dog, a descendant probably of a native wild species, 

 wliicli was not tamed at the beginning of tlie seventeenth 

 century, is truly indestructible, so that, after ten generations 

 its characters may still be detected in the cross breeds with 

 other races. Darwin very justly observes, that the coloured 

 rings on the feet, and transverse stripes frequently seen in 

 bred-horses, which are not observed in preceding generations, 

 may perhaps be traces reminding us of their origin. My 

 friend Desor directed my attention to the fact, that in the 

 young of perfectly black cats, the pedigree of which, during 

 several generations, was known, the primary fur was always 

 of a lighter shade, and presented a striped appearance, as 

 in the wild cat, and it was only after the lapse of a year that 

 the fur became perfectly black without presenting any stripes. 



Thus all facts combine to show, that by the side of individual 

 influences, there is in transmission another factor, namely 

 length of time, which gradually establishes a certain type 

 best adapted for a constant struggle for existence, and which is 

 the more permanent the longer the conditions for existence 

 remain unaltered. But the greater the fixity of this type, the 

 greater the demarcation from allied, and its hostility to other 

 types ; the gulf which separates it from the latter was incon- 

 siderable at first, but it gradually enlarged until it became im- 

 passable. 



Whilst thus the significance both of the natural and artificial 

 races of pure blood is certainly very great, we consider it at 

 the same time a step in a forward direction made by Nathusius 

 in distinguishing " raceless animals j" which, according to 

 this author, have arisen : " Either by the transportation of 

 natural races from their native country to foreign parts, not 

 offering them the same conditions for development, and where 

 their racial type was altered, without the assumption of a fixed 

 typical form ; or by the crossing of different natural races, 

 which in their progress are not led to a typical form ; or, also, 

 when artificial races are not attended to with the requisite 

 care, so that by hunger and other deprivations they relapse 

 into their original state." 



That from this chaos of raceless animals, partly by natural 



