646 APPENDIX B. 



by horse stallions had a mulish appearance in those cases where the mare had 

 previously given birth to a mule foal. Common heifers who have had calves 

 by a thoroughbred bull are apt thereafter to have well-bred calves even from 

 the veriest scrubs." 



Yet another very interesting piece of evidence is furnished by Mr. W. 

 Scdgwick, M.R.C.S., in an article on "The Influence of Heredity in 

 Disease," published in the British Medical Journal for Feb. 22, 1896, pp. 

 460-2. It concerns the transmission of a malformation known among 

 medical men as hypospadias. Referring to a man belonging to a family in 

 which this defect prevailed, he writes : " The widow of the man from whom 

 these three generations of hypospadians were descended married again, after 

 an interval of eighteen months ; and in this instance the second husband was 

 not only free from the defect, but there was no history of it in his family. 

 By this second marriage she had four hypospadiac sons and four hypospadiac 

 grandsons ; whilst there were seven grandsons and three great-grandsons who 

 were not mal-formed."] 



Coming from remote places, from those who have no theory 

 to support, and who are some of them astonished by the unex- 

 pected phenomena, the agreement dissipates all doubt. In four 

 kinds of mammals, widely divergent in their natures man, horse, 

 dog, and pig we have this same seemingly-anomalous kind of 

 heredity, made visible under analogous conditions. We must take 

 it as a demonstrated fact that, during gestation, traits of constitution 

 inherited from the father produce effects upon the constitution of 

 the mother ; and that these communicated effects are transmitted 

 by her to subsequent offspring. We are supplied with an abso- 

 lute disproof of Professor Weismann's doctrine that the repro- 

 ductive cells are independent of, and uninfluenced by, the somatic 

 cells ; and there disappears absolutely the alleged obstacle to the 

 transmission of acquired characters. 



Notwithstanding experiences showing the futility of contro- 

 versy for the establishment of truth, I am tempted here to answer 

 opponents at some length. But even could the editor allow me 

 the needful space, I should be compelled, both by lack of time 

 and by ill-health, to be brief. I must content myself with notic- 

 ing a few points which most nearly concern me. 



Referring to my argument respecting tactual discriminative- 

 ness, Mr. Wallace thinks that I 



" afford a glaring example of taking the unessential in place of the essential, 

 and drawing conclusions from a partial and altogether insufficient survey of 

 the phenomena. For this 'tactual discriminativeness,' which is alone dealt 

 with by Mr. Spencer, forms the least important, and probably only an inci- 

 dental portion of the great vital phenomenon of skin-sensitiveness, which is at 

 once the watchman and the shield of the organism against imminent external 

 dangers." (Fortnightly Review, April, 1893, p. 497) 



Here Mr. Wallace assumes it to be self-evident that skin-sensi- 

 tiveness is due to natural selection, and assumes that this must be 

 admitted by me. lie supposes it is only the unequal distribution 



