PAPILIO IIP, IV., V. 
black form. Mr. Walsh has stated that in Northern Illinois, both black and 
yellow females occur, though the black are five or six times more numerous than 
the yellow, judging from the careful observation of five years. But on visiting 
a clover field in southern Illinois he captured between seventy and eighty speci¬ 
mens, and every yellow one was a male. Professor Snow, in Kansas, tells me 
that there the black much outnumber the yellow. Mr. Aaron, at Maryville, east¬ 
ern Tennessee, writes that the species is abundant, but the yellow females are very 
rare, while the black ones are as plenty as the yellow males. And Messrs. Boll 
and Belfrage, in northern Texas, and professional collectors of large experience, 
say that the black female is much more numerous than the yellow one. All 
these observers, however, allow that the yellow females are found in their several 
districts. On the seaboard, Mr. H. K. Morrison, also an experienced collector, 
who has spent much time in the southeastern States, says, “ in Georgia half the 
females of Turnus are black.” And that he has a large number of specimens 
from Central and Northern Florida, “ and about one half the females are yellow.” 
But that among the mountains (Black Mountains) of North Carolina, the females 
were yellow. “ On my arrival at Henry’s, McDowell Co., N. C., I found the 
males and females, yellow form, July 15th to 30th, quite abundant and fresh. At 
the same place, August 25th to September 5th, I found the yellow form again 
abundant and fresh. I saw no black females. I caught one or two of these at 
Morganton, Burke Co., in July, but they were rare.” Within the zone inhabited 
by the two forms of female, neither has been known to produce a black male, nor 
is such an insect known to have ever been seen ; the black females produce yel¬ 
low males and mostly black females, only occasionally a yellow female appearing 
in the brood, so far as observed ; and the yellow females in very rare instances 
produce black females. It is not possible to distinguish a yellow male or yellow 
female by a black mother, from the same by a yellow mother, or the black females 
from each other, whether the mother was yellow or black. And, as a rule, the 
separation of the two forms of female is complete. Intermediate examples do 
sometimes occur, but they are exceedingly rare. In the hundreds of this species 
which I have bred, there never appeared one such, and in the field I have met 
but three or four, and these are chiefly represented on Plate V. The ochra- 
ceous female given on Plate IV. (Fig. 4), was bred by Mr. John Akhurst, at 
Brooklyn, N. Y., from eggs laid by a yellow female. Mr. Akhurst informs me 
that from this yellow female, inclosed in a box with a branch of sassafras, he 
obtained about eighty eggs, and raised from them a large number of butterflies. 
Two females were deep ochraceous, and two were black, all the rest being yel¬ 
low. This is remarkable, considering that Brooklyn is near the extreme northern 
limit of the black form. It is very unusual, in a district in which the two forms 
