Plants of Large Genera Have Wider Ranges Than Varieties

There is reason to believe that the 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 catalog of plants, fourth edition, 63 plants which he considers as so closely allied to others 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 catalog, 53 acknowledged varieties are recorded, and these range over 7.7 provinces,. whereas the species to which these varieties belong range over 14.3 provinces.