Type European. British Columbia, near Wharnock Station, _A. J. Hill_; Vancouver, _Macoun_ (as _ramosissimum_); Blacktail Deer Creek, Yellowstone Park, _Knowlton_. The latter is quite peculiar in appearance and approaches _robustum_. None of the specimens exactly agree, but will come here better than elsewhere. _The Ames Botanic Laboratory, North Easton, Mass._ THE SPECIES-CONCEPTION AMONG THE TERNATE BOTRYCHIUMS. By Willard N. Clute. Living as I do in the midst of a region rich in specimens of the ternate _Botrychiums_, I have taken more than ordinary interest in the discussion of the relative rank to which the various forms should be assigned. After considerable study of the subject which has consisted of a careful balancing of the degree of differentiation in each form, as well as an examination of much material both in the herbarium and in the field, I have come to certain conclusions which I purpose to set down here. Before the separate forms are discussed it may be well to say a few words on the variations of _Botrychium ternatum_ in general. It is a noticeable fact that all the so-called new species of this section of the genus, have been based primarily upon the cutting of the sterile part of the frond. This is all the more remarkable since there are probably no other genera in which species are founded on the minor outlines of a mere leaf. One has but to turn to nature in any clime to see that leaves are not invariably of the same shape. Note the wide variation in the moonseed, the hollyhock, the sassafras, and some of the buttercups among flowering plants, and if it be contended that the cases are not parallel, take as further illustration the blood-root, which, like the _Botrychium_, produces but one leaf a year, and note the cutting of its single leaf. If all these forms of _Botrychium_ are species, why have not the forms of the bloodroot been segregated? Moreover, if we are to recognize these forms of _Botrychium_ as species, why should we not also recognize as such the three hundred forms of _Athyrium filix-foemina_, or the hundred or more forms of _Scolopendrium_? It is unavailing to say that these latter are mere gardeners’ varieties, for we have it on the authority of Mr. Druery, who is familiar with them all, that a large number come true from spores. Experiments with flowering plants have shown that the thickness of leaves and the amount of cutting of their edges, may be altered by different degrees of moisture, sunshine, etc., to which they are exposed, and we may infer as much for the ferns. This being so, it is not difficult to account for the slight variations in cutting exhibited in plants from widely separated points in the United States.