58 
SPECIES OF LAEGE GENEKA 
Chap. II. 
we shall see how this may be explained^ and how the 
lesser differences between varieties will tend to increase 
into the greater differences between species. 
There is one other point which seems to me worth 
notice. Varieties generally have much restricted ranges: 
this statement is indeed scarcely more than a truism, 
for if a variety were found to have a wider range than 
that of its supposed parent-species, their denominations 
ought to be reversed. But there is also reason to believe, 
that those species which are very closely allied to 
other species, and in so far resemble varieties, often 
have much restricted ranges. For instance, Mr. H. C. 
Watson has marked for me in the well-sifted London 
Catalogue of plants (4th edition) 63 plants which are 
therein ranked as species, but which he considers as so 
closely allied to other species as to be of doubtful value : 
these 63 reputed species range on an average over 6*9 
of the provinces into which Mr. Watson has divided 
Great Britain. Now, in this same catalogue, 53 acknow¬ 
ledged varieties are recorded, and these range over 7*7 
provinces; whereas, the species to which these varieties 
belong range over 14*3 provinces. So that the acknow¬ 
ledged varieties have very nearly the same restricted 
average range, as have those very closely allied forms, 
marked for me by Mr. Watson as doubtful species, but 
which are almost universally ranked by British botanists 
as good and true species. 
Finally, then, varieties have the same general cha¬ 
racters as species, for they cannot be distinguished from 
species,—except, firstly, by the discovery of intermediate 
linking forms, and the occurrence of such links cannot 
affect the actual characters of the forms which they 
connect; and except, secondly by a certain amount of 
