692 THE AMERICAN NATURALIST.  [VOL: XXXII. 
edge would be too strong, that the lower plants become specifi-. 
cally changed more easily and quickly than the higher; but 
although this is what we should expect from their more rapid 
individual growth, I am not able to cite any actual observations 
which can settle the question ; for, as you know, the school of 
botanists, which may be called the school of ready transforma- 
tionists, have a fatal tendency to accept unskillfully conducted 
or otherwise faulty observations as convincing proofs. Others, 
it is to be feared, err on the other side, and are not sufficiently 
ready to admit metamorphoses in different species of the lower 
plants. Probably the truth lies between the two. The meta- 
morphoses to which I now refer are, of course, in the normal cycle 
of individual development and should not be confused with the 
differentiation into races and species, but of necessity our views 
as to the latter must be influenced to some extent by our atti- 
tude towards the former. 
If we turn to the second word of our definition which needed 
explanation, and attempt to say what is meant by like indi- 
viduals, we find ourselves wholly at sea. Even if we agree 
that the likeness must be morphological and not physiological, — 
that does not help the matter at all. No two individuals are 
ever absolutely alike in morphological characters, and the ques- 
tion is one of comparative likeness only. Systematists may 
agree that certain characters are more important than other 
characters, but they would never agree as to what characters 
are important enough to be regarded as specific in comparison 
with those which are only racial. In fact, when we come to 
the point, we find that most systematists do not in practice 
distinguish species from races on the ground that the former 
are practically constant, whereas the latter are not, but rather 
on the ground that they regard the characters which they use 
to distinguish species as more important than those which 
they are willing to accept as merely racial. 
But what is more important and less important is a question 
not only of individual opinion at any given time, but it is also 
a question which depends on the means of analysis at our dis- 
posal, and these change from time to time. Surely there never 
lived a better systematist than Elias Fries, and at the time of 
