On the origin of the genus Anthocharis, dz. 
(= Euchloe, Hb.) 
By T. D; A, CockEereLi 
These delicate little butterflies, belonging to the genus An/fhocharis 
of Boisduval, seem at first sight very aberrant members of the Pzeris 
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 Pers, 
I have been driven to the conclusion that Az/hocharis 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 continent. 
In stating the facts which have seemed to me to support sucha 
view, it will be useful to review the peculiarities of the genus Az/hocharis, 
and show how they may have arisen as offshoots from the stock from 
which the genus Pverzs has also directly come. 
Single-broodedness.—\n Europe, Pierts bryonie of the Alps and far 
north is generally assumed to be the one-brooded ancestor of the double- 
brooded P. api 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 zafz group in North America, we have 
still the assumed primitive type, drvonze, and likewise the forms oleracea 
and zenosa to represent the European zapi—so far the analogy is com- 
plete—but then we are met with what seems a strange anomaly, Pverzs 
virginiensis, a delicate pale-winged form, appearing as a rare aberration 
in New York and Ontario, but actually as a spring-emerging one-brooded 
species in West-Virginia,—-just exactly as if it were an Amfhocharis, in 
fact! From this I think we get a clue as to the origin of Anthocharis— 
it did not arise from a one-brooded arctic form like P. dryvonie, but was 
rather a branch from a stem which was probably even shen double- 
brooded—and that accounts for its pallor and delicacy of structure, as 
fits an insect of the temperate zone. 
Orange-tips. —Those species of Anthocharts which I regard as com- 
ing nearest to the primitive type of the genus,* do not present orange 
tips, but since these orange patches are so characteristic of many species 
it will hardly do to overlook them. In the first place, they are developed 
in the males—which seems to show that they are of the nature of second- 
ary sexual characters, and have perhaps been perpetuated as such from 
* See also Darwin, “ Descent of Man,” 2nd Ed., p. 312. 
