WCP2751

[1]

London Hotel

Poole

9^th April 1896

Dear Mr Wallace,

I hope this may reach you before I arrive. I had intended to send it [to] you before but have been fully occupied. I want to talk it over with you among other things. It is a very condensed and sketchy statement but may Serve[sic] its purpose as an avant courier.

Yours Sincerely | Lloyd Morgan [signature]¹

1) In addition to what is congenitally definite in Structure[sic] or mode of response, an organism inherits a certain amount of modifiability or plasticity.

2) Natural Selection Secures

1) Such congenital definiteness as is advantageous to the Species[sic]:

2) Such innate plasticity as is advantageous to the individual.

[2] 3) The organism is subject to

1) variation of germinal origin

2) modification of environmental origin

4) NeoLamarckians contend that modification in one generation is a source of variation in the next

5) It is here suggested that persistent modification through many generations though not a source of variation may be favouring condition to variation.

6) Let us suppose that a group of organisms belonging to a plastic species is placed under new conditions of environment.

7) Those whose innate plasticity is equal to the occasion survive. They are modified. Those whose innate plasticity is not equal to the occasion are eliminated.

8) Such modification takes place generation after generation but as such is not inherited.

9) In the meanwhile, however, and concurrently, any congenital variations antagonistic in direction to these modifications will tend to thwart them and to render the organism liable to elimination; while

10) Any congenital variations Similar[sic] in direction to these modifications will tend to support them and to favour the individuals in which they occur.

[3] 11) Thus will arise a congenital predisposition [to] this modifications[sic] in question.

12) The longer this process continues the[?] more marked this predisposition and the greater the tendency of the congenital variations to conform in all respects to the persistent plastic modifications; while

13) The plasticity [illeg.] continuing in operation the[?] modifications become [illeg.] further adaptive.

14) When relatively perfect adaptation is reached (the conditions remaining relatively uniform) natural selection will slowly yet surely bring the congenital variations up to the level of such adaptation.

15) Thus plastic modification leads and variation follows: the one paves the way for the other.

16) In the absence of such innate plasticity as will meet the new requirements of the changed environment the individuals succumb and the species becomes extinct (as in many fossil types.)

17) The NeoLamarckian, fixing his attention first on the modification and Secondly[sic.] on the fact that organic effects Similar[sic.] to those produced by the modifications [4] gradually become congenitally stereotypic assumes that the modification as such is inherited.

18) It is here suggested that the modification as such is not inherited but is the condition under which congenital variations are permitted and are given time to reach the fully adaptive level.

19) Such a mode of origins meets Romanes difficulty concerning co-adaptation.

20) It may also be suggested that when congenital definiteness of adaptation is reached, variations there from having been continually eliminated, the tendency to variation is diminished; but that when plastic modification occurs, variations in a similar direction being permitted in[?]tendency to variation is increased. In other words: Constantly eliminate variations and you get a Survival[sic.] of the relatively invariable; Permit the perpetuation of variation, and you get a survival of the variable.

C.L.M. [signature]