160 The Philippine Journal of Science 1916 
and that even the degree is beyond our power of measurement, 
the particular number of steps between the Flagellate and the 
Angiosperm loses all possible importance. We may then agree 
that, on the one hand, the species that occupy the world to-day 
are, each and every one of them, products of an exceedingly long 
series of selected variants or mutants; but, at the same time, 
we may also all agree that species may be so defined that natural 
selection is never immediately responsible for their origin. 
In conceding that natural selection may not be immediately 
responsible for the origin of the “species” we may discover, I 
am not detracting one particle from the claim that it is ultimately 
responsible for the presence of every plant and for every typical 
and normal structure of every plant that any man can find any- 
where in the world. Among each season’s crop of variations, a 
few may endure because they are particularly fit to endure. 
These are naturally selected. The vegetation of the world to- 
day has been selected, and reselected, countless times, out of the 
crops of each season of past time. Though we may define a 
species in such a way that natural selection is not this year 
responsible for the majority of the species on any particular 
mountain top, there is no mountain top where it is not respon- 
sible for practically the whole of the vegetation — responsible for 
its particular form as well as for its presence. By defining 
species in a way that removes a large part of them from the 
scope of immediately past selection, we leave the vegetation of 
the world made up — as it actually is — almost entirely of a small 
minority of all species. For the vegetation of the world in every 
conspicuous aspect and attribute, natural selection is entirely 
responsible; and even though we accept definitions that make 
natural selection not responsible for single specific characters 
of single small groups of plants, we still leave it responsible 
for the most of the characters of every individual among these 
plants, and leave it (natural selection) with entire ultimate re- 
sponsibility for the presence of each, even of these rare excep- 
tions ; for, without the sanction of natural selection, their parents 
would never have born progeny. 
I turn now to a few r of the details of Doctor Willis’s papers. 
Quoting from page 328, “In cases where we get two large and well- 
deffined groups in a family, we may compare their degrees of rarity, when 
the difference between them is what is usually looked upon as an adaptation. 
For example, in the Rubiaceae it is usually supposed that the sections with 
fleshy fruits are more recent than those with dry. But on the other hand 
the former is supposed to be an adaptation to enable the seeds to be easily 
dispersed.” And from page 329, “It is evident that the fleshy fruit has 
