160 The Philippine Journal of Science me 



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 denned 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 ho 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 of the details of Doctor Willis's papers. 



Quoting from page 328, "In cases where we get two large and well- 

 defined 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 

 d 1S persed." And from page 329, "It is evident that the fleshy fruit has 



