428 Ill. SEGREGATES AND 
often bewilder us by their ill-defined pettiness, and doubtless drive 
away in disgust some of the students who might have become 
botanists under more encouraging conditions. The tendency of 
the practice must be to make book-botany attractive only to the 
lowest class of minds which can engage in science at all; the 
minds which devote themselves exclusively to minute details, and 
which find their right vocation there, simply because incapable of 
anything higher. <A few aggregates will here be taken as special 
instances, and will be traced quasi-historically into their smaller 
segregates; the names of which now so greatly puzzle us, over 
and above the difficulty in distinguishing the things intended, one 
from another. 
It is trusted that some few such expositions will not only bring 
home to readers the botanico-topographical difficulties consequent 
on the changes, but may serve also in some degree as warning 
suggestions, that other mischiefs and inconveniences will arise 
through the making or adopting of such changes with ill-considered 
haste. It will become apparent, that practically a good deal of 
confusion is the immediate result, chiefly through the name- 
transfers and misnaming which too often have accompanied well- 
meant changes supposed to be elucidations ; and that the taste for 
this kind of innovation has already introduced much confusion 
into our nomenclature, by making the same name mean quite 
different things,— applicable to one species at one date, —to 
another, not identical species, at a second date, —to a third still 
varied species at a third date, and so on. 
The expositions must be understood as examples only, on the 
rule of “ex uno disce omnes.” This work would lose its title and 
intended character of ‘Compendium,’ if similar expositions in 
detail should be entered into for any considerable number of the 
many other old aggregates, which of late have been converted into 
their more numerous modern segregates. And yet, in order 
clearly to understand these recent segregates, and to connect them 
at all with the past records of their localities, and too often even 
with the present records, such details ought to become known 
to botanical investigators. In the absence of that knowledge, 
