Instinct 



Siberia, and the Alps of Europe, the veins above and below are 

 strongly bordered with blackish, and the ground-color of the 

 hind wings and the apex of the fore wings on the under side are 

 distinctly bright yellow. 



(e) Newfoundland variety acadica, Edwards, Plate XXXIV, 

 Fig. 19, $ . This form is larger than the others, and in markings 

 intermediate between pallida and bryonice. The under side in 

 both sexes and the upper side in the female are distinctly yellowish. 



Early Stages. — These are well known and have often been 

 described, but some of the varietal forms need further study. 



The species ranges from the Atlantic to the Pacific, and from 

 Alaska to the northern limits of the Gulf States. 



(7) Pieris rapse, Linnaeus, Plate XXXV, Fig. 3, ? ; Plate II, 

 Figs. II, 1 2, larva; Plate V, Figs. 58, 65, chrysalis (The Cab- 

 bage-butterfly). 



Butterfly, — This common species, which is a recent importa- 

 tion from Europe, scarcely needs any description. It is familiar to 

 every one. The story of its introduction and the way in which 

 it has spread over the continent has been well told by Dr. Scud- 

 der in the second volume of "The Butterflies of New England," 

 p. 1 175. The insect reached Quebec about i860. How it came 

 no man knows; perhaps in a lot of cabbages imported from 

 abroad; maybe a fertile female was brought over as a stowaway. 

 At all events, it came. Estimates show that a single female of this 

 species might be the progenitor in a few generations of millions. 

 In 1863 the butterfly was already common about Quebec, and was 

 spreading rapidly. By the year 1881 it had spread over the eastern 

 half of the continent, the advancing line of colonization reaching 

 from Hudson Bay to southern Texas. In 1886 it reached Denver, 

 as in 1884 it had reached the head waters of the Missouri, and it 

 now possesses the cabbage-fields from the Atlantic to the Pacific, 

 to the incalculable damage of all who provide the raw material for 

 sauer-kraut. The injury annually done by the caterpillar is esti- 

 mated to amount to hundreds of thousands of dollars. 



INSTINCT 



Two city fathers were standing in the market-place beside a 

 pile of cabbages. A naturalist, who was their friend, came by. 

 As he approached, a cabbage-butterfly, fluttering about the place 



280 



