140 Mr. H. E. Dresser. 



Pyrrhula cinerascens in which the male has the under parts 

 silvery grey without any red, and this last species is alsa 

 found in north western America, if, as I believe, Pyrrhula 

 cassini is specifically identical with it. 



Amongst the Larks there are some interesting instances of 

 climatic variation, thus the Crested Lark and the Short-toed 

 Lark vary extremely in colouration according to the nature of 

 the soil they frequent, but besides these individual varieties 

 one finds in north Africa two species of crested Lark fairly 

 distinct from our bird, Galerita macrorhyncha and Galerita 

 isabellina ; and of the Short-toed Larks we have in Europe 

 besides Calandrella brachydactyla, Calandrella miyior, Calan- 

 drella bcetica, and Calandrella pispoletta, and of this last a 

 distinct form of a pale grey colour, Calandrella leucophoea, 

 inhabits the sandy dry steppes of Central Asia. 



I could continue these examples of variation in species, and 

 of the way they branch out into allied but specifically distinct 

 forms through the whole of the groups represented in Europe, 

 but the above remarks will, I think, tend to give my hearers 

 some insight into the matter, and if they will themselves 

 collect series of examples they will be able to record many 

 interesting facts tending to throw more and more light on the 

 subject. The two most prominent causes of the variation one 

 observes in species are the interbreeding of closely allied 

 forms, and the difference in climate and locality in the habitat 

 of the birds. The subject of variation arising from the inter- 

 breeding of allied species is one which has hithertohad but scant 

 attention, and one which certainly deserves the utmost investi- 

 gation. It has long been known that interbreeding does occur 

 amongst birds in a wild as well as in a semi-domesticated 

 state, but it has chiefly been recorded amongst the Columboe 

 Gallince and Anseres. In a domestic or semi-domestic state it 

 is well known that the Pigeons and the Pheasants will cross 

 with allied species belonging to the same group, and the 

 offspring being fertile, will, by interbreeding again, merge off 

 into endless varieties, but in a state of nature the ofispring 

 are, comparatively speaking, seldom fertile. It is known now 

 that all the various forms of the domestic Pigeon are evolved 

 by selection and interbreeding from the common Rock Dove, 

 Columba livia, and should any of these forms be let go and 

 become wild they will, in the course of a short time, revert 

 back to the original species from which they have sprung. 

 The common Barndoor Fowl, also, if turned out will revert 

 back to the original wild form, and curiously enough the male 

 will cease to crow, as this note, so characteristic of our 

 domestic cock, is not uttered by the wild bird. The Pheasant,, 

 also, which in our coverts interbreeds so much that it is now 



