COLIAS IV. 
State. In the highlands this Colias is restricted in the number of its annual 
broods, and the form Eurytheme is either unknown, or very rare, according to 
the locality, the species being mainly represented by Keewaydin. And at cer¬ 
tain levels throughout the State the upland races come in contact with the low¬ 
land, — the digoneutic, practically limited to a single form, meeting the poly- 
goneutic and polymorphic race; and by the consequent cross-breeding the 
thorough separation of the lowlanders into seasonally distinct forms is inter¬ 
rupted and can never become so definite as on the vast plains which occupy 
Texas, and the regions to the immediate north and south of it. (See Note.) 
IV. In Texas and the regions adjoining there are no inequalities of surface 
sufficient to affect the general result, and this species has lor ages been subject 
to the most favorable climatic and geographic conditions for the development of 
polymorphism. There are four annual broods, the earliest, flying from November 
to February, consisting of Ariadne , the next of Keewaydin , the third ol an intei- 
grade, and the last of Eurytlieme, the separation being marked. If either form 
appears in any degree out of its season, it is not in sufficient numbers to invali¬ 
date the rule. The species here is truly polymorphic and seasonally so. 
Keewaydin, throughout the range of the species, is the most constant of the 
three forms, and I should consider it the winter form and therefore the primitive. 
But where the species is polygoneutic, a second winter form, Ariadne, has arisen, 
and in some districts where it is di- or tri-goneutic, an intermediate variety, 
strongly tending towards this second winter form, sometimes manifests itself. 
The case is much as in Papilio Ajax, which has one summer form Mcircellus, but 
two winter forms, Telamonides and Walshii, the first the primary, the other sec¬ 
ondary. Application of cold to chrysalids of any of the forms of Ajax causes 
Telamonides to appear, and similar experiments made with chrysalids of this 
Colias will be apt to show which is the original winter form. 
The 'resemblance between Eurytheme and j Philo dice I have spoken of, and 
probably every variety and sub-variety of each form of the first of these species 
can be paralleled in the other, color alone excepted. The variety of Philodice 
shown on Plate III., of Colias, Figs. 2, 3, corresponds with Ariadne; Figs. 1, 2, 
Plate II., correspond with the typical Eurytheme. Even the appearance of the 
dog’s head, characteristic of Colias Ccesonia, and not unfrequently to be seen in 
the female of Eurytheme, occasionally appears in Philodice. Albinic females ap¬ 
pear in every brood as in Philodice. In that species these females are as com¬ 
mon in the early spring brood as in any of the.later ones, although the contrary 
has been stated by authors; and judging from the number of albinos received 
by me from many quarters, the same is true of Eurytheme. 
The larvcB of Eurytheme and Philodice are scarcely, if at all, distinguishable 
