Excerpt from The Variation and Correlations of Certain Taxonomic Characters of Gryllus

I wish also to thank, at this time, those who have helped me to secure data. That part of these data which is used in the present discussion, together with the constants calculated from them, are given in the Appendix. Unless otherwise stated all the measurements are from mature females.

I. The Taxonomy of Gryllus Native to Eastern States.

De Vries (1904) considers that specific characters are usually sharply defined against one another. They are, according to him, separate qualities more often than different degrees of the same quality. This is not true of the crickets, as they are now named. One species does not possess "units" which the others of the same genus lack, but one species differs from the others merely in the "degree" of common characters. Presence or absence of characters (e. g., mobility of tibia! spines, teeth between these spines, etc.) are considered of generic or higher value.

Davenport & Blankinship (1898) have expressed the expectation that biometry would furnish us with a "precise criterion of species" and would, in part at least, clear away the haziness which exists in the taxonomy of most orders of both plants and animals. This haziness is most pronounced where species are based, as they are in the Gryllinfe, upon differences in size of characters common to the different species, and not upon de Vriesian "units." When starting this work I hoped that a statistical study of relatively large collections might bring out several sharply defined groups upon which we could logically fix specific names. The extremely frequent appearance of "GryUus sp. " in otherwise detailed taxonomic lists emphasizes the need.

De Saussure, one of the foremost taxonomists of the genus, gave up sharply defining the limits of his own species.

Beutenmilller (1894), considering the crickets of New York and vicinity, groups luctuoem, nigra, and neglecte with pennsylvanice, and angete with abbreviate. As I understand it, he is still of the opinion that we have in northeastern United States only these two species, and that their distinguishing mark is the long ovipositor (18 to 21 mm.) of abbreviatus as compared with the short one (12 to 15 mm.) of pennsyl-vanicus. The former is more apt to occur in sandy places and to mature in the spring.

Lochhead (1897) was unable to see any difference between abbreviate and pennsylvanice, although he worked over a large variety of characters, including wing venation. However, fixing upon the fact that "one form, luctuose, has hind wings which project like tails behind the wing-covers, " and that this character occurs in both sexes, he was inclined to call this form a distinct species and to refer everything else of this region to abbreviate.

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