Dr. Latuam’s Efjay on the T sitib or Windpipes of Birds. 123 
is figured, among others, in the Berlin Tranfactions, by Dr. Bloch, as 
above referred to in the Synonyms. 
From the fcarcity of the Mergan/er tribe in this kingdom, fuffi- 
cient opportunities rarely occur to enable us to afcertain many points 
about them as might be wifhed for. Iam, however, now inclined 
to believe, as hinted in another place*, that the Gas/ander and Dun 
Diver form but one fpecies, and that the former is the male bird. 
What has, I believe, led us hitherto to fuppofe otherwife, is the cuf- 
tom of this fpecies of the two fexes feparating after breeding time ; 
the o/d males affociating together in one flock, and the females, with 
the young birds Gietibilt Seaton, forming a feparate company ; 
fufficiently accounting for the flocks of thefe latter being moft nu- 
merous: from this caufe, and the plumage of the male being for a 
certain feafon not unlike that of the female, and efpecially diffec- 
tion proving that many males are always among them, the won- 
der ceafes that the birds in queftion fhould have been fet down by 
many writers for different f{pecies. 
In Germany thefe birds are fufficiently plentiful, and the ornitholo- 
gifts of that country have written much concerning them ; the refult 
of which is, that the Mergan/er is confidered by them asthe male, and 
the Dun Diver the female, and the Caffor of Linnzus not at all dif 
tinét, nor otherwife than the young bird. It would take up too 
‘much room here, in this Effay already fufficiently long, to detail 
what Dr. Pallas +, Profeffor Beckmann t, and Dr. Otto §, have faid 
on this fubjet in the Berlin Tran/faétions ; but I fhould not do thefe 
Gentlemen juftice, did I not recommend the perufal of their various 
Differtations, which may be read with equal pleafure and advan- 
‘tage. 
® Gen, Syn. vi. p. 423- + Befch. der Berl. Nat. Fr. ii. p. §51- 
+ Befch. der Berl. Nat. Fr. i. p. 170. § Id. iii. p. 456. 
R2 AXVIE. 
