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Mr Bernard, On the Unit of Classification 
On the Unit of Classification for Systematic Biology. By 
Henry M. Bernard, M.A. 
(' Communicated by Mr A. E. Shipley.) 
[j Read 11 November 1901.] 
My object in appearing here to-day is not merely to awaken 
an interest in the purely abstract problem of ideal classification, 
but to awaken an interest which will, I hope, sooner or later result 
in a practical reform of method. So far as I can see, zoologists are 
face to face with an ever increasingly serious practical difficulty. 
This difficulty is at present felt in very varying degrees, which 
depend upon the stability of the forms on which we are engaged. 
Those working with constant forms know nothing about it, whereas 
in my own case it actually brought my work on the stony Corals 
to a standstill. To state very briefly the difficulty as it affects 
my own work. ‘ Species 5 as distinct genetic groups, or indeed as 
anything even approaching distinct genetic groups, are not dis- 
coverable. However striking the form -differences within a genus 
may be, their variations are so great and so numerous and inter- 
graded that no trustworthy conclusion can be arrived at as to 
their value for the purposes of genetic classification, at least until 
we have a far wider survey of forms than any at our disposal 
to-day. And yet we have no other formula for our attempts at 
classification than that supplied by the binominal species name of 
Linnaeus, which compels us either to group the specimens into 
‘ species ’ or to leave them alone. 
My experience during the past year, during which I have 
spent a great deal of time in working at this problem, this paper 
being about the fifteenth attempt I have made to clarify the 
subject, while at the same time I have been discussing it both 
publicly and privately, has led me to see that though the imme- 
diate difficulty is a practical one and requires a practical solution, 
it must be attacked primarily from its philosophical side. I see quite 
clearly that had I confined myself merely to stating the difficulty 
I should have gained a good deal of sympathy; but I did not do 
so, I went further and made a definite constructive proposal 
involving a reform of our methods of naming specimens. We all 
know that, provided we only stick to the work, a practical way 
out of a practical difficulty is always sooner or later suggested by 
the work itself ; and that happened in this case. After a seven 
years’ hopeless attempt to give scientific precision to what was, 
