CiiAP. VI. THEIR PARENTAGE. 201 



arc at least now unknoAvn. This double accident is so ex- 

 tremely improbable that the assumed existence of so many 

 abnormal species would require to be supported by the 

 strongest evidence. On the other hand, if all the races are 

 descended from C. livia, we can understand, as will hereafter 

 be. more fully explained, how any slight deviation in structure 

 which first appeared would continually be augmented by the 

 preservation of the most strongly marked individuals ; and as 

 the power of selection would be applied according to man's 

 fancy, and not for the bird's own good, the accumulated 

 amount of deviation would ceitainly be of an abnormal 

 nature in comparison with the structure of pigeons living in 

 a state of nature. 



I have already alluded to the remarkable fact that the cha 

 racteristic differences between the chief domestic races are 

 eminently variable ; we see this plainly in the great difference 

 in the number of the tail-feathers in the Fan tail, in the deve- 

 lopment of the crop in Pouters, in the length of the beak in 

 Tumblers, in the state of the wattle in Carriers, &c. If these 

 characters are the result of successive variations added together 

 by selection, we can understand why they should be so 

 variable : for these are the very parts which have varied 

 since the domestication of the pigeon, and therefore would be 

 likely still to vary; these variations moreover have been 

 recently, and are still being accumulated by man's selection; 

 therefore they have not as yet become firmly fixed. 



Fifthly. — All the domestic races pair readily together, and, 

 what is equally important, their mongrel offspring are per- 

 fectly fertile. To ascertain this fact I made many experi- 

 ments, which are given in the note below; and recently 

 }yir. Tegetmeier has made similar experiments with the same 

 result. 19 The accurate Xeumeister asserts that when dovecots 



19 I have drawn out a long; table of doubtedly have thus united all. The 



the various crosses made by fanciers case of five distinct breeds being 



between the seA r eral domestic breeds blended together with unimpaired fer- 



but 1 do not think it worth while pub- tility is important, because Gartner 



lishing. I have myself made for this has shown that it is a very general, 



special purpose many crosses, and all though not, as he thought, universal 



were perfectly fertile. I have united rule, that complex crosses between 



In one bird five of the most distinct several species are excessively sterile. 



races, and with patience I might un- I have met with only two or thres 



10 



