 Muhlenber ia, Volume 
96 g 4 
certain to occur between two extremes which appear to be dis- 
tinct. He suggests that the best method would be to grow the 
“two apparent extremes within the natural environment of the 
apparent intermediates.” 
The third heading is ‘“The Taxonomic Treatment of Groups 
assumed to be of Lower Rank than Species.” He says “there 
is perhaps no taxonomic subject on which greater diversity of 
opinion and practice exists than in the arrangement and nomen- 
clature of groups of individuals not accorded full specific value.” _ 
“Tt has been very evident that these described groups are of un- 
equal value, some resembling the assumed typical groups more, 
some less, and in a good many instances very littler ‘The gen- 
eral results of these attempts to dissect nature has been embar- 
tassing, because when a subsequent student takes up the group 
he is wholly unable to determine from any description that can 
be written where any given individuals would have been group- 
ed by the previous author, unless he has access to the actual 
specimens which the previous author studied. . . The result 
shows conclusively that for practical taxonomic purposes it is 
not desirable to attempt to define a great many of these minor 
groups.” 
“Tt is evident, I think, that our taxonomy has been based 
on the fundamental error that the plant world is to be regarded 
as divisible into smaller and smaller groups, rather than follow- 
ing nature and proceeding on the theory that it is built up of 
greater and greater ones.”’ 
“Tf, as now seems more probable than a few years ago, spe- 
cies are made up of elementary species, or races, and that these 
are being increased by mutation, there can be no end to the 
nuinber of such groups produced.” 
He suggests that the term ‘race’ be employed to distin- 
guish these elementary species, and the discontinuing of all 
other terms intended to designate groups of assumed lesser rank 
than species, and concludes with four propositions. 
