314 
SPECIES OF BIRDS. 
atricapilla, or blackcap, Sylvia garnila of Bechsteifl’ 
and also with species of Troglodytes and PerdriS' 
They shew such marked differences, that we ® aB 
determine them with ease after a little practice. Tb® 
principal differences are here again in the head an® 
bill. It has been ascertained, that different forms #* 
crania determine different species of mammalia, but fh at 
the determinations are less strikingly marked in tb® 
smaller animals, as those of the mouse, shrew, and ba t 
tribes, than in the larger ones, but that, in all these, tb® 
teeth afford good distinctive characters. It is worth/ 
of remark, that, as the bill in birds is equivalent to tb® 
teeth in quadrupeds, that differences in the manducatory 
organs, in both classes, afford specific characters. 
Many ornithologists, says Brehm, will consider the®® 
distinctions either as useless, or as leading to needle® s 
minutiae, — an opinion he considers as erroneous. *** 
illustration of the importance of such distinctions, h® 
remarks, that the very precise determination of the sped*® 
of birds affords interesting disclosures in regard to tb® 1 ® 
migrations. Hitherto, says he, it has been believed tb® 
the Strix bubo, or great horned owl, Cinclus, or wat®( 
rail, wild duck, ( Anas boschas ,) Regulus, or gold-crest® 
wren, and many others, remained in his neighbourhood’ 
(Renthendorf,) during the winter, which is not tb® 
case ; for accurate determination of the species b ® 5 
shewn, that their great-horned owl leaves them, and j ts 
place is taken in the winter season by that from tb® 
north; that a kind of wild duck, which rarely breed 6 I 
in Central Germany, but is a native of the Faro Island*’ 
is common in the open brooks and rivers in the win 1 ® 1 
season ; that the Northern Cinclus occurs more f r ®J 
quently in winter in their mountains, streams, a 1 ! 
brooks, xlian the German Cinclus ; and that it is rarely 
the case that the gold-crested wren, which breeds th® 1 '®’ 
remains over the winter, its place being taken by tb 
northern species, which has wandered to them aero® 
the Baltic. 
These facts, (allowing Brehm’s determinations to “ * 
correct,) shew, in a very interesting manner, the imp 01 
