712 REV. DR. GOODACRE ON THE CHINESE GOOSE. [NOV. 18, 



of the Grey-lag, how came there to he wild Chinese birds 1 To which 

 it may be replied, Is it certain that there are any ? may not the sup- 

 posed wild specimens be only feral 1 If so, it would be a somewhat 

 similar case to feral "chequered" Rock-Doves, as far as regards 

 breeding for generations without reverting to the original type. 



The fertility between these two forms of Domestic Geese reminds 

 me forcibly of the same thing between divers so-called species of 

 wild Pheasants, as shown by Mr. Tegetmeier ; and I am inclined to 

 accept his solution of the mystery as applicable to Geese also. 



Of course I do not pretend to be able to prove the specific iden- 

 tity of the Common and the Chinese Goose ; but I think what I have 

 said may be taken as evidence that such a theory is really not so 

 absurd as it may at first sight appear to be. 



The doctrine of specific identity of certain very diverse forms of 

 animals appears to me one deserving of careful study ; and every 

 case that may be supposed to illustrate it in a marked way seems of 

 importance towards attaining what we ought all to be seeking — the 

 truth. Hence the fertility of the offspring of Common and Chinese 

 Geese may teach us lessons of general interest and importance in 

 zoology. 



Great variations of a species are chiefly to be observed in domestic 

 animals ; but we err if we suppose they do not occur among wild 

 ones, although doubtless many are masked from our observation by 

 their receiving specific names when in reality they are nothing more 

 than varieties or geographical races. 



In conclusion I will briefly state that there are three points, in the 

 cross-bred Geese themselves which we have been considering, which 

 incline me to look on them as mongrels. According to the laws of 

 hybridity one would have expected the trachea to be intermediate 

 between the parent forms (as it is in hybrids of the Musk-Drake 

 with the Common Duck), and the knob on the bill and the stripe on 

 the neck to be quite suppressed ; now none of these things happen. 



I shall be glad to hear that any zoologist is willing to turn his 

 attention towards solving the mystery that certain so-called hybrids 

 produce fertile offspring (which most do not) ; for this seems always 

 to happen in cases in which the right to specific distinction is ques- 

 tioned by some naturalists. 



Wilby Kectory, Norfolk, 

 September 1879. 



