Dr. LatuHAm’s Effay on the Trachee or Windpipes of Birds. 97 
found: and further, that it is the ma/e alone which has this mark 
of difcrimination ; for although many birds may be found having 
the female plumage, in which the labyrinth 1s) equally confpicuous 
with others poffefling that of the other fex, yet I will venture to 
affirm, that this part differs not from that of an old male, except in 
refpect to the offification being lefs complete; and again, that in 
every fpecimen with fuch enlargement of ¢rachea, or. labyrinth, 
the defies, an indubitable mark. of the male fex, will invariably be 
found to accompany, it. 
Among other errors, the G/aucium ae pea Mis or Morillon of the 
French, has been recorded as a diftinét fpecies by many. This how- 
ever may eafily be proved a fallacy by diffection, asthe bird is no 
other than the Go/den Eye in imperfect feather; for this fpecies does 
not attain the adult plumage for at leaft the firft feafon, perhaps 
longer. Another bird, paffing under the name of Morillon, proves, 
by the fame teft, to be the young of the Tufted: Duck 3) and a third 
called Morillon alfo, merely a young Scaup, which I have more than 
once identified. Befides, were the ‘difference of bill alone in thefe 
birds attended to, it could not fail to decide the mattér, as they are 
greatly unlike each other in this particular, notwithftanding the: 
external colour of feather might: lead a fuperficial obferver to think 
them the fame. | adhe, hima 
The wild Swan is not greatly unlike the tame fpeciesi in refpeét to plu- 
mage, the difference of bill at firft fight'appearing to be the chief ex- - 
ternal charaéteriftic, infomuch as to deceive fome Naturalifts into the 
fuppofition of their being varieties only of one and the fame fpecies*; 
Fi TIOGA ON Mt : PIG LGW Ob (ut but 
* M, de: Buffon was apprifed.of the difference of internal ftrugturé, but,accounts for it: 
on a,fingular principle, when he obferves in.anote!:» “ Selon, Willughby cette particularité 
‘© de conformation eft propre au cygne fauvage, & ne fe trouve point laméme dans le cygne. 
s* domeftique, ce que femble fonder ce que nous allons rapporter de Ja difference de leur, 
_ Vou. IV, 1@] “ voix, 
