RECENT PROGRESS OF SYSTEMATIC BOTANY. 47 
species and primary varicties instead of limiting himself to orders and tribes, 
They are at the present day amongst the most important botanical works. 
They are required by the systematist for the identification of plants, and by 
the general naturalist as the source whence he is to derive the data he requires 
respecting individual species in theoretical, geographical, physiological, or 
applied botany. This preparation has been recognized as the best exercise 
for the young botanist ; and monographs of difficult orders have been re- 
ceived as most valuable contributions from some of the most eminent heads of 
the science. 
Our requirements for a complete monograph are analogous to those we 
expect in ‘ Ordines’ and ‘ Genera Plantarum,’—methodical arrangement, tech- 
nical diagnoses and descriptions, indications of geographical distribution, 
*‘ qualitates et usus,” and occasional notes on affinities and systematic limits, 
including an investigation of synonyms, well selected illustrations adding 
always to the practical value. The technical diagnoses and descriptions for 
the use of the systematist ought invariably to be drawn up in botanical Latin ; 
the more general matter would usually be more readily written, and often 
much more intelligible, in one of the three general modern languages. 
_ This similarity required in the histories of orders, genera, and species 
has not, however, been hitherto generally acknowledged, and could not even 
have been admitted so long as it was believed that there was an essential 
difference between the groups—between the definite fixity of species and 
the more arbitrary limitation of genera and orders. In early systematic 
works, therefore, whilst the definitions of orders and genera were single 
and in ordinary phraseology, it was thought necessary, in the case of species, 
to give a double definition—a diagnosis containmg the supposed fixed 
characters, by which the species could be absolutely tested, and therefore 
expressed in the ablative absolute, and a description admitting all classes of 
characters in the ordinary form of phraseology. As the number of specics 
increased, greater extension was habitually given to both diagnosis and de- 
scription, till they became unwieldy for use, without some short indication 
of the most striking points to be attended to. This has been done in two 
ways, either by prefixing to the group of species described a tabular clavis or 
a short conspectus of the contrasted characters to which attention is specially 
called, or by italicizing them in the long diagnosis. The former course en- 
tails often the useless repetition of the same characters three times over, in 
the clavis, in the diagnosis, and in the description ; the latter, seeing that the 
italicized words are usually adjectives, often occasions confusion and loss of 
time in searching for the substantives to which they belong. Now that it is 
laid down that there is no more absolute fixity in a species than in an order 
or genus, the complication is no longer necessary ; there is no more need of an 
absolute test in the one case than in the others. In all we want a short 
indication of the most prominent contrasted characters for approximate or 
preliminary determination, prefixed to the detailed description for subsequent 
verification. 
These short characters are given in three different forms :—Ist, a tabular 
clavis, more or less on the dichotomous principle, as is now frequently exem- 
plified in local floras; 2ndly, a conspectus prefixed to the whole group of 
‘species; 3rdly, the short character prefixed to each description, In 
elaborate monographs, where the descriptions are long, the conspectus is pro- 
bably the most satisfactory form ; in more concise ones, where the descrip- 
tions are short, the tabular clavis will be found more useful. In synopses, 
swhere the descriptions are reduced to occasional notes or limited to new 
