944 The American Naturalist. [November, 
THE LIMITS OF ORGANIC SELECTION. 
By Henry FAIRFIELD OSBORN, 
OPENING A DISCUSSION BEFORE THE SECTIONS OF GEOLOGY AND BOTANY 
i ROIT: 
The object of this paper is to set forth certain views as to the 
limits of the supplementary natural selection hypothesis re- 
cently proposed by Prof. James Mark Baldwin, Prof. C. Lloyd 
Morgan and myself as “ Organic Selection.” 
The line of thought which led me to Organic Selection 
was as follows: The distinction between the ontogenic and 
phylogenic variation was drawn in my mind in 1894, because 
it was evident in the current researches upon variation by 
Weldon, Bateson and others, and in the line of reasoning fol- 
lowed by Cope, Ryder, Scott, Osborn and other Neo-Lamarck- 
ians that the importance of such a distinction was being over- 
looked. There are three main types of variation: First, for- 
tuitous congenital variations which are the temporary and transi- 
tory fluctuations around a mean, Second, ontogenic variations? 
which are the departures from normal or typical development 
arising during ontogeny; they include all the effects of the reac- 
tion of the individual to new or disturbed conditions of life 
which rise in the course of individual growth and may disap- 
pear with the death of the individual; the mooted question 
whether ontogenic variations are or are not heritable does not 
affect their distinctness. Third, phylogenie variations, also con- 
genital, which belong in the phylum, as observed principally 
in fossil series; they are stable and inheritable departures from 
ancestral types towards a new type; they correspond with the 
“mutations” of Wagner and Scott, i. e., they are. departures 
‘Alte und Neue Probleme der Phiylogenese. Ergeb. d. Anat. ti. Entwick., 
Merkel u. ‘Bonnet, III Band, 1893, pp. 584-625. : 
* Prof. C. Lloyd Morgan has proposed to apply the word “ modification,” vati- 
ously used by Cope, Bailey and other authors, to what is above described as acta 
togenic variation” and to restrict the term “ variation ” to congenital variation. 
This excellent suggestion subseryes clearness, and should be adopted by all writ- 
ers, 
