State Agricultural Society. 
533 
to them; and it being a native insect of our country we know its 
natural food must be some one or more of our indigenous plants, 
on which it wholly subsisted before the cabbage and our other culti¬ 
vated vegetables were introduced upon this continent. I find it is 
nourished upon the water-cress or yellow rocket, the Barharea vul¬ 
garis, much more extensively than upon any other plant, wild or 
cultivated. Our botanists have usually regarded this as a native plant 
•of this country; but as it is also a European plant some have sup¬ 
posed it was probably originally introduced here from abroad. It 
occurs in such abundance in our moist lowland meadows and also in 
dry gravelly upland soils that it has every appearance of being a 
native plant. And this insect feeding upon it in such numbers as it 
does, is a further indication that it is an indigenous plant. It, more 
than any other member of the vegetable kingdom, appears to be the 
natural food-plant of this butterfly. 
This plant starts into growth so early in the spring that its radical 
leaves become sufficiently expanded to meet the wants of this butter¬ 
fly when it first makes its appearance. And it is principally upon 
this plant that the first generation of each year is reared. It, how¬ 
ever, is no doubt able to sustain itself upon several other wild plants 
of the order Crucifer®. And later in the season, when the cabbages, 
turnips and radishes in our gardens are sufficiently grown to be 
adapted to its wants, it begins to bestow its eggs upon them. It some¬ 
times invades the cabbage when the plants are only six or eight 
inches high with but five or six leaves put forth upon them. 
When engaged in depositing its eggs it dies very slowly just above 
the tops of the plants, alighting upon a leaf here and there; and so 
intent is it upon the work in which it is engaged that it will some¬ 
times come quite near a person, without manifesting any fear, or 
quickening its flight to move away. 
Alighting, it stands upon the edge of the leaf, and bending its 
body downward it touches the tip to the under surface of the leaf, 
planting an egg thereon, placing it from an eighth to a quarter of an 
inch inward from the edge of the leaf. From one to three eggs, 
placed slightly apart from each other, are thus glued to the underside 
of the leaf, when it again takes wing and searches out another leaf 
such as it desires. 
The eggs are nearly one-twentieth of an inch in length and twice 
as long as thick. They are shaped like a sugar-loaf, being cylindrical, 
with the base cut oft' transversely and the opposite end gradually 
tapered to about a third of the thickness and then abruptly and 
