April 7, 1905.] 



SCIENCE. 



533 



and of evolutional development. This fact 

 has been brought forcibly to our attention 

 again by the stimulating -work of de Vries. 

 There are collective species, elementary 

 species and other grades. Our formal 

 nomenclature in practise recognizes only 

 two grades — 'species' and 'variety,' with 

 no two persons agreeing which is one or 

 the other. If there are such differing 

 grades in nature, then we must accept the 

 fact and adopt new technical words for the 

 various grades. This has not been done, 

 at least not in practise, because we have 

 not yet sufficiently clear ideas to enable us 

 to do so. These varying grades of species 

 and varieties are the results of processes of 

 evolution, and some, if not all, of these 

 processes are still in operation. Therefore, 

 the new definitions of species-concepts must 

 rest on physiological or functional grounds, 

 not merely on morphological and anatom- 

 ical grounds. 



Many of us feel that the present methods 

 of nomenclature and description will be 

 outgrown, for these methods are made for 

 the herbarium and the museum, rather 

 than for the field. It is a most suggest- 

 ive commentary that the botanist may 

 know the 'species' when it is glued on an 

 herbarium sheet, but may not know it when 

 growing. The nurseryman or gardener 

 may know it when growing, but not when 

 it is in a herbarium. Thi§ is not merely 

 because the botanist is unfamiliar with the 

 field, or the gardener unfamiliar with the 

 herbarium; these men have different fun- 

 damental conceptions of what a species is; 

 they use different 'marks,' one morpholog- 

 ical, the other largely physiological. I be- 

 lieve that the gardener is nearer the truth. 

 I recall a characteristic remark made by 

 my master, Sereno Watson, when, in the 

 confidence of youth, I asked whether a cer- 

 tain binomial would be accepted a hundred 

 years from now. He shrugged his shoul- 



ders and said quietly, 'I don't know; they 

 may call plants by numbers then. ' 



1 have no intention of proposing any new 

 plan of nomenclature— that would only 

 amuse you. I merely feel, as you do, that 

 a change is imminent. Perhaps we shall 

 hold to our main species-groups for his- 

 tory's sake, and then designate minor 

 groups in terms of their qualities. If we 

 find it to be true that there are fluctuating 

 varieties and mutations of differing gen- 

 eses, then we must assuredly represent 

 these facts in nomenclature and taxonomy. 

 Very likely we shall adopt a scheme wholly 

 different from the current binomial plan 

 for designating one or the other, or perhaps 

 both. We may adopt quantitative names 

 — having determined the main lines of dif- 

 ferentiation, may express each variation in 

 names of more or less. I look for some 

 such method to result from the statistical 

 quantitative study of variation. Let me 

 draw an illustration also from plant-breed- 

 ing practise. The horticulturist and the 

 agriculturist have been holding to the for- 

 mal or conventional idea of 'variety.' We 

 will suppose that the farmers of a region 

 have grown Jones's Giant White Corn. 

 They have bought and sold and planted 

 this name. They have fed it to the pigs; 

 and the pigs may have thrived or may not, 

 according as the corn contained much or 

 little food value. The name is of no value 

 to the pigs; and, in fact, it is of no real 

 value to the farmer unless it is a guarantee 

 of some particular excellence. Now, the 

 name Jones's Giant White designates corn 

 of certain color and shape of ear and of 

 kernel— features which really mean noth- 

 ing to the farmer, whereas the starch-con- 

 tent or the protein-content may mean 

 everything. The new plant-breeding does 

 not tiy to produce a new 'variety' so much 

 as a series of generations that shall have 

 greater efficiency. We shall have, perhaps, 

 fifteen per cent, protein corn, or seventy- 



