THE FOUR INSEPARABLE FACTORS OF EVOLUTION. 



303 



variations) 



an 



afforded 



(Habit and Instinct, 315): " Though there is no transmission of modifications due to individual dIm 

 ticity, yet these modifications afford the conditions under which variations of ,?1 - 



an opportunity of occurring and of making themselves felt in race progress." 



Another phase of the possible results of the action of " coincident selection" 

 is illustrated in what Baldwin has to say regarding orthoplasy. 



i 



Orthoplasy (Gr. ApM*, straight, + *\*™ 9 a fold): Ger. orthoplasic; Fr. orthopla&ic- Hal. 

 orloplasia. Determinate or definitely directed evolution under the laws of natural and organic 

 selection (see those terms). [Diagram.] . . . This term has been suggested and adopted by the 

 advocates [i. e., Baldwin] of the theory of organic or indirect selection as opposed to Orthogenesis 

 (q. v.), the latter having a vitalistic meaning, and implying Lamarckian heredity. Orthopliiy 



cases 



presence 



adfi 



The successive formulae of the inseparable factors corresponding with the 

 hypothesis of " coincident selection'' are as follows: 



H E 1 S = first, or environmental phase of initiation, in which change of habit is rendered 



necessary. 



H O 7 E 1 S = in which a change of environment is followed by a change in ontogeny, resulting 



from the formation of a new habit. 

 H 1 O 2 E 1 S = fourth phase in which hereditary predispositions arise in heredity or saltations 



which happen to coincide with the modifications introduced by the changes of 



habit and ontogeny. This is the u coincident variation " of Morgan. 

 H* O 3 E 1 S 4 «= final phase in which selection acts upon all cases in which heredity coincides with 



ontogeny. 



The following citation is from the original statement 2 of the hypothesis of 

 coincident selection by Osborn in 1896: — 



"... the adult form of any organism is an exponent of the stirp, or constitution -f the environ- 

 ment. If the environment is normal the adult will be normal, but if the environment (which includes 

 all the atmospheric, chemical, nutritive, motor and psychical circumstances under which the animal 

 is reared) were to change, the adult would change correspondingly; and these changes would be so 

 profound that in many cases it would appear as if the constitution, or stirp, had also changed. Illus- 

 trations might be given of changes of the most profound character induced by changes in either of the 

 above factors of environment, and in the case of the motor factor or animal motion the habits of 

 the animal would, in the course of a life time, profoundly modify its structure. For example, if the 

 human infant were brought up in the branches of a tree as an arboreal type instead of as a terrestrial, 

 bi-pedal type, there is little doubt that some of the well-known early adaptations to arboreal habit 

 (such as the turning in of the soles of the feet, and the grasping of the hands) might be retained and 

 cultivated; thus a profoundly different type of man would be produced. Similar changes in the action 

 of environment are constantly in progress in nature, since there is no doubt that the changes of en- 



V1 ^ I l n if nt anc * the nabits which it so brings about far outstrip all changes in constitution. This fact, 

 which has not been sufficiently emphasized before, offers an explanation of the evidence advanced by 

 v. ope and other writers that change in the forms of the skeletons of the vertebrates first appears in 

 ontogeny and subsequently in phylogeny. During the enormously long period of time in which habits 

 induce oncogenic variations it is possible for natural selection to work very slowly and gradually 

 upon predispositions to useful correlated variations, and thus what are primarily ontogenic variations 

 become slowly apparent as phylogenic variations or congenital characters of the race. Man, for 

 instance, has been upon the earth perhaps seventy thousand years; natural selection has been slowly 

 operating upon certain of these predispositions, but has not yet eliminated those traces of the human 

 arboreal habits, nor completely adapted the human frame to the upright position. This is as much an 

 expression of habit and ontogenic variation as it is a constitutional character" (pp. 141-142). 



' Baldwin J. Mark, Orthoplasy. Dictionary of Philosophy and Psychology, vol. II, The Mac- 

 millan Company, 1902, p. 251. 



2 Abstr. [A Mode of Evolution requiring neither Natural Selection nor the Inheritance of Ac 

 quired Characters.] Trans. N. Y. Acad. Sci., vol. XV, Mar. 9 and Apr. 13, 1896, pp. 141-142, 148. 



