18 REPORT OF THE SECRETARY. 



than tbe random description of numerous nevr species." The catalogue 

 forms an octavo vohime of 324 pages, and inchides a full index. 



Another paper published in 1878, to be mentioned, is a " Botanical 

 Index," prepared by Prof. Sereno Watson, of Cambridge, Mass. The 

 purpose of this index is to furuish references to whatever has been pub- 

 lished respectiug the plants of North America, under their Linnean spe- 

 cific names, in works or papers that may be classed as belonging to sys- 

 tematic botany. For the region west of the Mississippi and for British 

 America, the literature of which is almost wholly fragmentary and 

 greatly scattered, and on account of which especially the work was orig- 

 inally begun, it is intended to be complete. And it is essentially so also 

 for the eastern flora, where, however, there is not the same necessity 

 that the citations should be exhaustive. To avoid the perpetuation of 

 errors it was desirable to eliminate false species and to correct wrong 

 determinations wherever they had gone upon record. This could not 

 have been thoroughly done without a com]ilete revision of the flora 

 itself, which was of course out of the question; nevertheless it was ren- 

 dered to a considerable extent possible as respects the Avestern Ilora, by 

 the author's connection with the "Botany of California"; and in many 

 other cases he was enabled to decide upon the validity of species, and 

 to verify determinatioiis or to settle doubtful synonymy by comparisons 

 of specimens themselves in the collection of the Harvard Herbarium. 



The delays that have arisen in the preparation of the volume have 

 not been without compensation in the far more complete and satisfactory 

 results which were only thus made possible; and the deficiencies of the 

 earlier portions are largely supplied by the copious appendix, which 

 makes the whole essentially complete, up to the date of publication. 

 The portion now printed covers the ground of Torrey and Gray's Flora 

 of North America, which was pul^lished in 1838-1840, and is now so com- 

 pletely out of date as to leave this portion of our botany nearly as much 

 in need of revision as any other. Until such revision can be made 

 (and it must still be delayed some years), the " Index " will necessarily 

 be a partial substitute — in some respects sufficient, inasmuch as it shows 

 Avhat genera and species ai;e recognized as forming our flora, and also as 

 concerns the synonyuiy, which could not be given with any such com- 

 pleteness, withiu the limits of the desired revision, and moreover suffi- 

 cient in its references to all existing descriptions of those species. In 

 any given case, these descriptions may indeed be practically inaccessible, 

 or they may be incomplete or faulty, and it is herein that nothing can 

 be a substitute for a " Flora," which shall bring together into one vol- 

 ume perfected descriptions, together with such grouping of genera and 

 species as to indicate their natural affinities. For the preparation of 

 such a Flora, or for the study of any special portion ot the field, the 

 present Index will meantime be an important aid, giving as it Avere a 

 skeletonized history of each individual species, and affording a clue to 

 all that is known toward the needed filling out of the outline. The 



