No. 381.] THE CONCEPTION OF SPECIES. 695 
supposed to throw some light on present conditions. It is no 
disparagement to systematic botany to say that it should look 
towards physiology as its necessary supplement; for, on the 
other hand, physiology must lean on systematic botany in 
attempting to solve many of its problems, and the scientific 
basis of both rests on histology, morphology, in the modern 
sense, and embryology. The qualifications needed in a physi- 
ologist are so different from those required in a systematist 
that no one is warranted in speaking of one as of a higher 
grade than the other. If it has become the fashion in some 
quarters to assign the systematist to a secondary place, it can- 
not be attributed to the fact that his work is necessarily inferior 
in quality, but is rather due to the fact that in too many cases 
systematists have failed to recognize what should be the legiti- 
mate aim of their work. 
The utilitarian tendency is well shown by what has been said 
in speaking of bacteria and Saccharomycetes. Did time per- 
mit, and were the subject not one which would not readily be 
followed with patience by an audience at this late hour, other 
instances, especially in Ustilaginacez, might be given to illus- 
trate further the point in question. The bacteriologist bases 
his species on grounds which he thinks best suited to enable 
him to group together intelligently the plants he is studying, 
and it is nothing to him that others say that his species are 
not species, but races. After all, the question whether certain 
forms are to be considered species or races is in many cases 
merely a question of how much or how little we know about 
them. The races of one generation of botanists often become 
the species of the next generation, who, as they study them 
more minutely and carefully, discover constant marks not 
previously recognized. As systematic botany develops in the 
future, it may very well become the study of races rather than 
Species as we now consider them. In some cases, as in the 
Uredinacez, the time may be not’ far distant when this condi- 
tion of things will be reached. We also feel warranted in 
believing that hereafter physiological characters will assume 
even a greater importance than at present in the characteriza- 
tion of species. If there are some among my hearers who do 
