28 THE ZOOLOGIST. 



RELATIONSHIP OF SPECIES. 

 By H. Panton. 



(Continued from vol. xvii., p. 455.) 



About fifteen years ago I wrote a short paper as a kind of 

 summary of hybridisation, in which the results seemed to me, 

 as far as I could then gather, to tend to confirm the views I put 

 forward, and I cannot perceive that they do not apply equally to 

 the present time. I was then unaware that these different 

 degrees of hybridisation had been worked out and named by 

 Broca as long ago as 1864.* I will quote a good deal from my 

 old article on the subject. 



" Presumably, in the course of evolution, animals, when only 

 slightly changing from each other, produce fertile young or 

 mongrels ; but when in the course of time their differences 

 become intensified, they produce infertile young or hybrids ; and 

 finally, when still more changed from each other, they will be 

 unable to produce young at all. And again, presumably, as 

 these differences must grow gradually, there must be inter- 

 mediate states between these three stages, i. e., between the first 

 and second, when the produce will be occasionally fertile (more 

 or less) ; and between the second and third, when the contract- 

 ing animals will only occasionally produce young." 



Adding to the examples I then recorded, the table now 

 gives : — 



A. Animals producing fertile young (mongrels). 



Examples : Bison and Cow, Yak and Cow, Zebu and Cow, 

 Gayal and Cow, Jaguar and Leopard, Dog and Wolf, Dog and 

 Jackal, Brown and White Bears, Zebra (true) and Ass. Golden 

 and Amhurst Pheasant, Hooded and Common Crow, Pintail and 

 Mallard, Tufted Duck and Pochard, and various other birds. 

 (These correspond to Broca's Eugenesic hybrids, "being fertile 



;: ' On the Phenomena of Hybridity in the Genus Homo.' 



