But we shall hereafter return to this subject.
From these remarks it will be seen that I look at the term species as one arbitrarily given, for the sake of convenience, to a set of individuals closely resembling each other, and that it does not essentially differ from the term variety, which is given to less distinct and more fluctuating forms.

The term variety, again, in comparison with mere individual differences, is also applied arbitrarily, for convenience sake.
WIDE-RANGING, MUCH DIFFUSED, AND COMMON SPECIES VARY MOST.
Guided by theoretical considerations, I thought that some interesting results might be obtained in regard to the nature and relations of the species which vary most, by tabulating all the varieties in several well-worked floras.

At first this seemed a simple task; but Mr.H.C.
Watson, to whom I am much indebted for valuable advice and assistance on this subject, soon convinced me that there were many difficulties, as did subsequently Dr.Hooker, even in stronger terms.

I shall reserve for a future work the discussion of these difficulties, and the tables of the proportional numbers of the varying species.

Dr.Hooker permits me to add that after having carefully read my manuscript, and examined the tables, he thinks that the following statements are fairly well established.