RE CENT PROGRESS OF SYSTEMATIC BOTANY, 53 
territory, and its botany has been partially worked up monographically by A. 
Gray, geographically by Sereno Watson, Porter, and others ; but the great 
mass of data collected are scattered over so great a variety of publications as 
to render them almost useless to the general botanist. We cannot even 
approximately fix upon the boundary-line to separate the North-American 
from the very different Mexican flora to the south-west. Northward it 
should, if it is wished to make it really instructive, extend, like the two other 
great floras, to the limits of vegetation ; eastward and westward the Atlantic 
and Pacific afford definite boundaries. But the comparative degree in which 
the external connexion with Europe and Asia is broken off by the two oceans, 
the causes of the difference observed, as further illustrated by recent paleon- 
tological discoveries, the effect of the north-and-south ridge of mountains and 
other causes in separating eastern and western races within the territory, and 
many other important elements in the history of plants can only be satisfac- 
torily investigated with the aid of such a comprehensive, methodical, and 
geographical flora as we are in hopes the distinguished Harvard- University 
botanist is now preparing. ° 
6. Sprcrric Descriptions, detached or miscellaneous. 
Had I to report only on the progress,"and not on the present state also, of 
systematic botany, I should here stop, for the great majority of recent detached 
and miscellaneous descriptions are almost: as much impediments as aids to the 
progress of the science. I have too often in my Linnean Addresses, espe- 
cially in those. of 1862 and 1871, animadverted on the mischief they produce 
to enter now into any details ; I can only lament that the practice continues, 
and is even rendered necessary by considerations not wholly scientific. Hor- 
ticulturists must have names for their new importations. It is due to tra- 
yellers who, under great perils and fatigues, have contributed largely to sup-' 
plying us with specimens of the vegetation of distant regions that the results 
of their labour should be speedily made known; it is even important to 
science that any new form influencing materially methodical arrangements 
should be published as soon as ascertained. But all this is very different 
from the barren diagnoses of garden-catalogues, and the long uncontrasted 
descriptions hastily got up for the futile purpose of securing priority of name. 
I own that I have myself erred in the want of sufficient consideration in the 
publication of some of the species of ‘ Plante Hartwegiane ;’ and some descrip- 
tive miscellanea, even by men who stand very high in the science (such as 
Miquel’s ‘ Prolusiones,’ above referred to, and Baron von Mueller’s ‘ Frag- 
menta’), are rendered comparatively useless from their utter want of method. 
Whilst, therefore, discouraging as much as possible all such detached publi- 
cations of new species, I would admit their occasional necessity, but suggest 
the following rules as the result of a long practical experience :— 
No detached description of a new species should be ventured upon unless 
the author has ample means of reviewing the group it belongs to; and if any 
doubts remain of its substantive validity, he should refrain from giving it a 
name till those doubts are cleared up. 
The description, when given, should be full, but contrasted, and accom- 
panied by a discussion of affinities with previously known species, and an 
- indication of the place the new one should occupy in the several monographs 
and floras in which it would be included. 
An illustration of the new plant, with analytical details, should never be 
neglected where circumstances admit of it. 
In conclusion, if I am correct in the views I have taken of the desiderata 
