690 THE AMERICAN NATURALIST. [VOL XXXII. 
now, for their work is recent and has been carried so far beyond 
that of previous experimenters that it must require a consider- 
able number of years before we can expect the work to be 
repeated by others. So far as the experiments have been 
repeated, as in the case of P. coronifera and P. coronata, it has 
been confirmed. ? 
Enough has been said to show that the conception of species 
by those who are doing the most advanced work in fungi is 
much more flexible than it used to be, and significance is to be 
attached to the fact that the number of those who, as viewed 
by the typical systematic botanist, hold very heterodox views 
is increasing. The explanation is to be sought in the fact that 
descriptive botany in certain groups of plants has reached a 
point where the ordinary morphological characters no longer 
suffice to classify what we know or wish to know about the 
plants themselves. It was my privilege eleven years ago to 
address what was then the biological section of the Association 
on a subject somewhat related to that of to-day, and my closing 
sentence then was: “Following the prevailing tendency in 
business affairs, the question they [botanists] ask of plants is 
not so much, ‘Who is your father and where did you come 
from ?’ as, ‘What can you do?’”’ 
The tendency noticed eleven years ago is even more marked 
at the present day. As compared with the times of which I 
attempted to give a sketch in my opening remarks, I think we 
may truly say that whatever may be the case in zoology, in 
botany theoretical considerations with regard to evolution play 
a much less important part than they used to. In the case of 
such plants as Lycopodiacez, Equisetaceze, and their allies, and 
of certain orders of phanerogams, the ancestral question natu- 
rally remains as important as ever ; but, although papers on 
other orders of plants, accompanied by hypothetical genealogies 
and family trees of the banyan type, appear at not infrequent 
intervals in botanical journals, they are quite overshadowed n 
general interest by the papers on cytology, life histories, and 
physiology. That was not the case in the sixties, when nothing 
compared in interest with the question of the origin of species. 
While we cannot be too grateful to Darwin for having opened 
