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scientific worth. What we do want is the careful delimitation of 

 distinct species or sub-species, not mere accidental variations. 

 This will not come with haste, and more than that, with inex- 

 perience ; some of it will come from familiarity with plants in 

 the field in two continents in which allied species grow ; some of 

 it will come from the sfudy of extensive suites in the larger herb- 

 aria ; some will come from the actual cultivation of plants under 

 different forms of environment ; some will come from widely 

 extended study afield in our own country for continued seasons 

 and in many places where different environment may modify 

 specific lines ; some will doubtless come from a study of the 

 younger stages of our native species. 



And this leads me to a line of work that will likely form a 

 vary conspicuous feature in the fern study of the next few years. 

 Comparatively few fern students are familiar with our native 

 species in their young stages, not only those that are in the first 

 or second leaf from the prothallus, but even when the plants are 

 half grown.* It is probable too, that new and possibly unex- 

 pected relationships will be brought out by such study. Surely 

 the work by Miss Slosson on the hybrid form just published 

 opens up an interesting field of work, as does the more elaborate 

 paper of Mrs. Britton and Miss Taylor on Vittaria. 



Anatomical studies such as that commenced by Mr. Waters 

 may well be extended so as to cover a wider range of species, 

 and new distinguishing characters between many species will 

 doubtless be found which now are difficult to distinguish. 



The range of American ferns, using America in its limited 

 sense including simply North America north of Mexico, repre- 

 sents too limited a fern flora to give a clear range of perspective 

 in regard to the broader questions of generic relations. Such 

 conceptions must come from a study of a fern flora more 

 diversified than our own, such as that of the American tropics, 

 of Hawaii, of Japan, or of the far East. During the next de- 

 cade it will become as easy to secure material for study from 



*\Vithin the p^st few days a specimen of voun? Ad'Cintum pcdatum has 

 been set me which was said "to resemble A. CapiUus-i'eneris" from its pin- 

 nate leaf. The reported discovery of A. capillus-veneris from Southern New 

 York a few years ago was based on a want of knowledge of the young stages 

 of this, our commonest species of fern, so different from the familiar outline 

 of the mature maidenhair, 



