WCP3796

Old Orchard, Broadstone, Wimborne

October 24, 1909¹

Dr. M. Cockerell

Your valuable information on the Floras of several states was received, and much appreciated. But I should like to know, if possible, what proportion of species [ought to] be deducted to bring the numbers into a fair comparison with those of Hooker, Bentham, and Asa Gray. The whole Rocky Mountain Flora including the ‘Plains’ was in 1885 only about 2000 — according to Coulter, and Brendel (Flora of Peoria) 1887 gives the State of Colorado as having 2245 sp. Surely the 2700 species now given must be almost wholly due not to discoveries of new species to the Flora, but to the splitting up of old, well-known species into a number of named forms. Just as in Brit. Plants, the increase of 376 species in 30 years was almost entirely due to this latter cause, the genera Rubus, Hieracium, and Euphrasia alone receiving 162 additions! Probably not more than 5 p[ercent] of the additions have been due to new discoveries of flowering plants.

My friend, Mr. W. H. Beeby tells me that in the latest Scandinavian Catalogue (Finland to Denmark) 2250 Hieracia out of a total of 5738 species named, are enumerated! This mania is being continually extended to hosts of other genera, so that all fair comparison with older lists or with those of botanists of less "splitting" tendencies, are quite useless.

Is not the 26,373 species and subspecies you give me for N. America (temperate!) also greatly exaggerated in proportion to the 9500 or 10,000 of Europe? Can you give me the number of species in Boulder County? And also its area?

Your last of Oct. 7, just received, about Mendelism. All these views as to what happens in the hypothetical constituents of the germ cells is quite beyond me. To me, if Mendelism proves anything it is that it is Nature’s method of preventing abnormalities, monstrosities, and mutations from ever forming species. The essence of species-formation is minute and varied, adaptation to changed conditions every kind often happening simultaneously. Mendelian characters appearing in nature rarely and singly, but being strongly hereditary without intermediates, are injurious to the course of evolution and are therefore rapidly exterminated.

Yours very truly, Alfred R. Wallace [signature]