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reared C. pomonella from a larva found feeding in a walnut. 

 C. pomonella being one of the most important insect pests, 

 it was of special interest to determine accurately the various 

 points in its economy, and it would therefore be desirable for 

 Mr. West to bring the specimen in question to one of the 

 meetings of the Society, or take steps to ascertain precisely 

 to what species it belonged. Mr. West stated that he would 

 bring the specimen with others, also bred from walnut, to 

 the next meeting ; and the matter stood over until then. 



The following paper, by Mr. T. D. A. Cockerell, was 

 read : — 



On the Origin of the genus Anthocharis, Bdv. ( = 

 Euchloe, Hb.). — These delicate little butterflies, belonging 

 to the genus Anthocharis of Boisduval, seem at first sight 

 very aberrant members of the Pieris stock, with their one 

 brood a year, narrow wings, and (in many species) orange 

 apical patches on the forewings. Yet in examining their 

 characters as compared with those of Pieris, I have been 

 driven to the conclusion that Anthocharis is by no means an 

 ancient genus — as genera go — and that it arose directly from 

 an old Pieris stock, and that probably on the American con- 

 tinent. In stating the facts which have seemed to me to 

 support such a view, it will be useful to review the peculiari- 

 ties of the genus Anthocharis, and show how they may have 

 arisen as offshoots from the stock from which the genus Pieris 

 has also directly come. 



Single-broodedness. — In Europe, Pieris bryonies of the Alps 

 and far north is generally assumed to be the one-brooded 

 ancestor of the double-brooded P. 7iapi of the lowlands, and 

 there is a tendency to assume that multiplication of the brood 

 is a direct result of a warmer climate, and the idea of a single- 

 brooded species arising from a double-brooded one seems not 

 often to be entertained. 



However, taking this same napi group in North America, 

 we have still the assumed primitive type, bryonies, and like- 

 wise the forms oleracea and venosa to represent the European 

 napi — so far the analogy is complete — but then we are met with 

 what seems a strange anomaly. Pieris virginiensis, a delicate 



