STATE AGRICULTURAL SOCIETY. 
429 
CURRANT. LEAVES. 
So long ago as the year 1781 Fabricius (Species Ins. ii, 93) 
described one of our American butterliies under the name Prngne, 
this, in the failles of heathen mythology, being the name of a sis¬ 
ter of Philomela who was said to have been changed into a swal¬ 
low. The deeply notched wings of this butterfly, having some 
resemblance to the forked tail of a swallow, perhaps suggested 
this name to Fabricius. Figures and descriptions of this butter¬ 
fly given by different authors since, have made it well known; but 
to this day we have remained unacquainted with the vegetation 
on which it is reared and the caterpillar from which it comes. In 
June last, two worms were sent me from J. M. Stevenson of Cam¬ 
bridge, one of the Vice Presidents of the State Agricultural 
Society, found with several others of the same kind feeding upon 
the leaves of his currant bushes. They proved to be the larvse 
of the Progne butterfly, and I am thus able to give the complete 
history of this species. I have also met with this butterfly in 
thickets bordering on lowland meadows, where it had probably 
been reared upon the wild black currant growing plentifully in 
these situations. A caterpillar found upon elms is described by 
Dr. Harris as being the larva either of this species or of the 
Comma butterfly ( C-album=comma , Harris.) It now appears 
beyond a doubt that it pertains to this latter species and not to 
the Progne butterfly under which it is placed. As the Progne is 
so intimately related to the Comma or White-C butterfly, and as 
this species feeds upon quite a variety of trees and plants, it is 
probable that further researches will show that the Progne is not 
restricted to the currant but subsists upon other kinds of vegeta¬ 
tion also. 
In very many of its marks no sensible difference exists between 
this butterfly and the White-C, and the collector who has but one 
of these species in his hands will be much perplexed to determine 
which of these names to give to his specimens, with only such 
brief and imperfect accounts as authors have commonly given 
to guide him. An exact description of each particular part of 
an insect is a valuable aid to the student in his researches, in every 
instance, and is specially required where different species are 
closely related. I have therefore endeavored to draw up such a 
description of this butterfly in its different stages as will serve to 
