11 



in such other herbarium as is indicated in the accompanying note. 

 The invariable rule has been to admit no name which has not an 

 extant specimen back of it. This has necessarily led to the ex- 

 clusion of a number of names of plants reported by earlier 

 botanists. In many of these cases the evidence is such as to 

 leave little doubt that the plants actually occurred as reported, 

 and probably many of them will be rediscovered. The names of 

 such plants are included in a supplementary list at the end of the 

 main catalogue, and each name so appearing should be con- 

 sidered as a challenge to the sagacity of present botanists until 

 the plant is again found." The main list includes a total of 

 1,563 species and varieties of Phanerogams and Pteridophytes. 

 The Engler and Prantl sequence is adopted, but the nomencla- 

 ture is essentially that of Gray's Manual and of the Kew Her- 

 barium. Whatever may be our differences of opinion as to the 

 claims of usage and expediency in nomenclatural matters (any 

 appeal to ethical grounds being logically denied to us who accept 

 an initial date for nomenclature), it certainly seems a violent per- 

 version of botanical history to retain longer for one of our com- 

 mon ferns the generic name Dicksonia, a name, which, so far as 

 the Pteridophytes are concerned, was first applied to two species 

 of ferns so different from ours that now, by common consent, 

 they are placed in an entirely different family. Even Sir William 

 Jackson Hooker,* a prince of " conservatives," once wrote, " The 

 name of Dicksonia surely, however, ought to be preserved to the 

 original D. arborescens (Balantiwn Kaulf. * * ),'"' and this posi- 

 tion is maintained by Diels in the Engler and Prantl Pfianzen- 

 familien and by other modern writers. From an international 

 standpoint, the attempts to preserve two Dicksonias in two dif- 

 ferent families of ferns are likely to prove a little confusing. 



Those who have seen Lycopodiiim Qiamaecyparissus growing 

 side by side with Lycopodiiim complanatum and so distinct as to 

 be readily distinguished at a distance of several feet and showing 

 not the least tendency to intergrade will be very sceptical as to 

 the propriety of considering it a variety of L. complanatum. 



At the close of the work are shorter lists, representing the more 

 important regional floras, in which we see an expression of the 



* Hooker, W. J. Genera Filicum, pi. 61 A [text] . 



