222 
ICTERUS AGRIPENNIS. 
the inhabitants of the eastern States, to whom the change 
of plumage in these birds is familiar, as it passes imme- 
diately under their eye ; and also to those who, like 
myself, have kept them in cages, and witnessed their 
gradual change of colour. That accurate observer, Mr 
William Bartram, appears, from the following extract, 
to have taken notice of, or at least suspected, this change 
of colour in these birds, more than forty years ago. 
“ Being in Charleston,” says he, “ in the month of 
June, I observed a cage full of rice birds, that is, of the 
yellow or female colour, who were very merry and 
vociferous, having the same variable music with the 
pied or male bird, which I thought extraordinary, and, 
observing it to the gentleman, he assured me that they 
were all of the male kind, taken the preceding spring ; 
but had changed their colour, and would be next spring 
of the colour of the pied, thus changing colour with 
the seasons of the year. If this is really the case, it 
appears they are both of the same species intermixed, 
spring and fall.” Without, however, implicating the 
veracity of Catesby, who, I have no doubt, believed as 
he wrote, a few words will easily explain why he was 
deceived : The internal organization of undomesticated 
birds, of all kinds, undergoes a remarkable change every 
spring and summer ; and those who wish to ascertain 
this point by dissection will do well to remember, that 
in this bird those parts that characterize the male are, 
in autumn, no larger than the smallest pin’s head, and 
in young birds of the first year can scarcely be dis- 
covered ; though in spring their magnitude in each is 
at least one hundred times greater. To an unacquaint- 
ance with this extraordinary circumstance, I am per- 
suaded, has been owing the mistake of Mr Catesby, 
that the females only return in the fall ; for the same 
opinion I long entertained myself, till a more particular 
examination shewed me the source of my mistake. 
Since that, I have opened and examined many hundreds 
of these birds, in the months of September and October, 
and, on the whole, have found about as many males as 
females among them. The latter may be distinguished 
