322 The American Naturalist. [April, 
as species those forms which have thus originated and which 
answer every demand of their definitions and practice. The 
proofs of the evolution of species, drawn from the accepted 
practice of the best botanists themselves, could be indefinitely 
extended. We need only recall the botanical confusion in 
which most cultivated plants now lie, to find abundant proof 
of the evolution of hundreds of types so distinct that the best 
botanists have considered them to be species; but other bot- 
anists, basing their estimate of species upon origins, have re- 
duced them or reincluded them into the form or type first 
described. Consider the number of species which have been 
made in the genus Citrus, comprising the various oranges, 
lemons, limes and the like. Recall the roses. The moss-rose 
and others would be regarded as distinct species by any bot- 
anist if they were found wild and if they held their characters 
as tenaciously as they do under cultivation. In fact, the 
moss-rose was long regarded as a good species, and it was only 
when its origin began to be understood that this opinion was 
given up. The earlier botanists, who were less critical about 
origins than the present botanists are, made species largely 
upon apparent features of plants, although their furidamental 
conception of a species was one which was created, as we find 
it,in the beginning. Yet, strangely enough, we at the present 
day profess to regard species as nothing more than loose 
and conventional aggregations of similar individuals and 
which we conceive to have sprung from a common ancestor 
at some more or less late epoch in the world’s history,—we 
make our species upon premises which we deny, by giving 
greater weight to obscurity of origin than we do to similari- 
ties of individuals. 
The fact is that much of the practice of systematic or de- 
scriptive botany is at variance with the teachings of evolution. 
Every naturalist now knows that nature does not set out to 
make species. She makes a multitude of forms which we, 
merely for purposes of convenience in classifying our knowl- 
edge of them, combine into more or less marked aggregations 
to which we have given the name species. Now and then we 
find in nature an aggregation of successive individuals which 
