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arthemis and archippus ; and an unnamed form between 

 astyanax and archippus. 



1. Proserpina. — Several different forms were figured, showing 

 a transition from those more like astyanax to those approach- 

 ing arthemis. The complete historical account included a full 

 summary of Scudder's strong grounds for concluding that 

 proserpina was a hybrid produced by the crossing of arthemis 

 and astyanax in the narrow zone where these two forms met 

 and overlapped. 



2. Arthechippus. — Only three examples, all males, and one 

 uncaptured specimen, were known to the author. 



3. The unnamed form. — Only three or four examples were 

 known. The sex of one only was given — a male. 



This first paper stated the facts and the problems, and 

 expressed the author's hope that he might succeed in reaching 

 their solution by experimental breeding. 



Field's second paper, " The offspring of a captured female 

 Basilarchia proserpina " (vol. xvii, No. 3, 1910, p. 87, 

 Plate VI), described a breeding experiment made in 1908 with 

 a female proserpina taken Aug. 14 at Springfield, Vt. The 

 butterfly refused all the available food-plants of arthemis, 

 but laid 31 eggs on wild cherry (Prunus serotinus) a food-plant 

 of astyanax. From these eggs 16 butterflies were bred — 9 (five 

 males, four females) proserpina closely resembling the mother, 

 7 (four males, three females) arthemis. The mother and a 

 pair of each type of the offspring were figured on Plate VI. 

 Thus " the observed facts accord with those noted by Edwards, 

 who in 1877 reared three arthemis and one proserpina from 

 eggs deposited by a proserpina captured in the Catskill region." 

 Furthermore, " these observations, considered in the light of 

 the Mendelian principles of heredity, give fresh support to 

 the view of Scudder (1889) and others, who have believed 

 proserpina to be a hybrid between arthemis and astyanax." 



The author considered that the male parent was probably 

 arthemis, inasmuch as Springfield " is north of the zone in 

 which proserpina ordinarily occurs." He also suggested " that 

 proserpina is a hybrid between arthemis and astyanax, in 

 which the dark coloring of astyanax incompletely dominates 

 the white band of arthemis." In the regular zone of proserpina 



