OF WASHINGTON. 49 
Mr. Schwarz read the following' note : 
ON A NEW FOOD-PLANT OF PIERIS RAP^E. On April 25th, Mr. Smith 
and myself made an excursion on the Bright-wood road, near Washington, 
and, while observing several specimens of Anthocharis gemitia, Mr. Smith 
mentioned that Mr. Schonborn had just found the eggs of Anthocharis 
on two species of Cruciferous plants, one of them being the common 
Winter Cress (Barbarea vulgarii). As several specimens of this plant 
were just then in blossom along our road we went at once to work to ex- 
amine them. Within a few minutes several butterfly eggs were found 
attached singly to the underside of the larger leaves, and more especiallv 
of such plants as grew isolated. Upon comparison, however, these eggs 
proved to be different from those of Anthocharis, and. in short, turned 
out to be those of the common Pieris rapes. The Winter Cress is not 
mentioned by Dr. Riley (Report of the Commissioner of Agri., 1883, P- 
in) among the known food-plants of the Imported Cabbage Butterfly, and 
also in Europe the same plant is not known to be attacked by this species. 
At least Kaltenbach does not mention it as such. 
Pieris r-apce as is well known is one of our earliest butterflies, appear- 
ing in the vicinity of Washington toward the end of March. As there are 
no cabbage plants in the fields thus early in the season, it appears highly 
probable that the first annual generation of Pieris larvae normally sub- 
sists on some wild plant, and this common Winter Cress will no doubt be 
found to be the principal food-plant of this species, though it cannot be 
asserted that it is the only food-plant thus early in the season. 
Mr. Lugger offered some remarks on the following subjects : 
1. Introduction of certain foreign insects into this country. 
He first found in 1878 some few specimens of the European 
Aphodius erraticus in the droppings of the Virginia deer which 
are kept in large numbers in Druid Hill Park, Baltimore, Md. 
In the course of a few years the Aphodius became very abundant, 
in early spring feeding upon the droppings of sheep. Now they 
are found in any excrement, and not alone in Druid Hill Park, 
but through a large extent of the neighboring counties. They 
are so numerous that they have actually replaced the formerly 
common Aphodius Jimetarius. He also mentioned the capture 
of a specimen of Agra cenea, a native of Surinam, and of various 
South American Cerambycidae in the vicinity of the wharves at 
Baltimore. 
2. On the fertilization of Cypripedium acaule and the Hard 
Maple [Acer.] He described the structure of the flower of our 
common Lady's Slipper, which permits an easy entrance to a 
