184 Life ami Letters of Francis (ralton 



42, Rutland Gate. Nov. 6/76. 



My iikak 1)akwin, Tliivc pnHit's i-c«cIi<h1 im- troiii the Contftnjmrary Review of my 'Theory 

 of Henxlity,' »o I can sjwre one, and a.s I know you like to mark what you reml, do not 

 c«re to n-turn it. I hope it will make my meaning more clear. The rcniiirk« prinUnl ii« a 

 note on p. 5, but which I ought to have put in the text, will meet what you wrote about the 

 Hymenoptera. 



I am most obliged for what you tell mc aliout Brown-Sequaiii ; I did not know of it, and 

 will hunt up the passage Uxlay. (Thanks for the reference, received this moniinj;.) 



I should be truly grateful for criticisms which might enable me to modify or make clear 

 before it is too late. Ever youi-s, Fhancis Galton. 



What a nuisance this motlern plan is, of sending proofs in sheet, and not in strip. One 

 can't amend freely. 



The paper which (ialton sent Darwin is entitled 'A Theory of Heredity.' 

 This memoir was in type for the Contemporanj Review in November 1875', 

 and was read before the Anthropological Institute in the same month. It 

 was revised and printed in the Journal of the Anthropological Institute 

 (Vol. V, pp. 329-48), and it is to this is-sue that we shall refer. The paper 

 follows generally the lines of the 'Blood-relationship' of 1872, e.xcept that 

 it still more definitely disairds 'Pangenesis' and cjists still further doubt on 

 the heredity of actpiired characters, and modification of offspring characters 

 by the use or disuse of the same characters in the parent. The paper there- 

 fore marks a further stage in Galton's dissent from Darwin's theory and 

 Darwin's views. Galton writes as follows : 



"The facts for which a complete theory of heredity must account may conveniently be 

 divided into two groups; the one refers to those inlwrn or congenital peculiarities that were 

 also congenital in one or more ancestors, the other to those that were not congenital in the 

 ancestors, but were actiuired for the first time by one or more of them during their lifetime, 

 owing to some change in their conditions of life. 



The first of these two groups is of predominant importance, in respect to the numlier of 

 well-ascertained facts that it contains, many of which it is po.ssible to explain, in a l)roiM] and 

 general way, by more than one theory base<l on the hypothesis of organic units. The second 

 group includes much of which the evidence is questionable or difficult of verification, and which, 

 as I shall endeavour tcj show, does not, for the most part, justify the conclusion commonly 

 derived frtmi it. In this memoir I divide the general theory of heredity into two parts, corre- 

 sponding respectively to these two groups. The first stands by itself, the second is supplementary 

 and subordinate to it." (pp. 329-30.) 



After noting that Darwin, in the chapter on Pangenesis in the Animals 

 and Plants..., had given the most elaborate epitome then extant of the many 

 varieties of facts which a complete theoiy of heredity must account for, 

 Galton states that his conclusions will differ e.s.sentially from Diirwin'K, and 

 continues: 



"Pangenesis appears more eM|M'cially f mined to account for the cases wliich fall in the 

 second of the above-mentioned groups", which are of a less striking and a-ssured character than 

 tboae in the first 'group, and it will be| seen that I accept the theory of Pangenesis with con- 

 siderable modification, as a stlpplemcntary and 8ulx>rdinate part of a complete theory of heredity, 

 but by no means for the primary and more important part." (p. .130.) 



' It appeared in that Review in the following n)onth. It was published also in the Revue 

 Seientiji^fue, T. x, pp. 198-205, 1870. 



* I.<ater on p. 347 Galton says that Pangenesis over-accounta for the facts of acquired modi- 

 fications and reparations. 



