256 NATURE-STUDY REVIEW [13:6— Sept., 1917 



the great number of species in this genus, as well as in others of the 

 subfamily, is really remarkable. With but few exceptions, this is 

 the case throughout the group. For example, in the tropical genus 

 Dismorpha there are over one hundred species, and perhaps fully 

 that many more yet unknown to science. In another genus 

 (Tachyris), nearly eighty species belong in the Old World, while 

 only one is found in this country, and in it the sexes are quite 

 different in their color-pattern. Those of another genus have been 

 called the "Whites;" they are of medium size, generally white in 

 color, with certain limited marginal markings, and, in one species at 

 least, conspicuous spots. 



The species generally known as the Cabbage Butterfly belongs to 

 this genus Pieris, it being Pieris rapoe. Writing about it in his 

 "Butterfly Book," Holland says: "This common species, which is 

 a recent importation from Europe, scarcely needs any description. 

 It is familiar to every one. The story of its introduction and the 

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

 Scudder in his 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 spread- 

 ing 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 estimated to 

 amount to hundreds of thousands of dollars." (p. 280). 



Again, some of the species of the subfamily are very small, some 

 being white upon their fore wings, tipped with bright orange with 

 black-spotted emarginations (Euchloe). Passing these and many 

 others, we meet with the genera Catopsilia and Kricogonia, created 

 to contain the "Great Sulphurs," which are very much larger 

 species, of a brilliant orange or yellow color and few markings. The 

 Cloudless Sulphur (Catopsilia eubule) is of a rich yellow color, and 

 measures some two and a half inches across. It is an insect of 



