66 Permanence and Evolution. 



sort, or among the handsomest, at any rate, 

 and therefore the most likely to be crossed with 

 them, in order to impress its -colour, as the 

 phrase is. In a number of instances Darwin 

 produced birds coloured like the rock dove by 

 crossing pigeons of various breeds and colours, 

 not known or supposed to have any cross, so 

 that either the colour sprang up spontaneously, 

 or the strains Darwin employed (about which he 

 does not seem to have known much in the way 

 of pedigree) were not so pure as he took them 

 to be. There is not much said in the remark 

 that "white fantails breed perfectly true, and 

 have never been known to show any other 

 colour." If pure bred, no doubt, but the question 

 is of the particular strain employed. It is also 

 true that intermediate forms can be found be- 

 tween the most remote breeds, and that some of 

 the breeds have had their characters intensified 

 by selection at no remote period ; but these 

 intermediate breeds, and these less characterised 



