Sir

As you seem inclined to yield to M^r. Galtons arguments as to the non-existence of Pangenetic gemmules in the circulating fluid I wish to point out some weaknesses in his position as well as to bring to your notice an important phase of your hypothesis.¹ As far as I can gather from the reports I have seen of M^r. Galton’s experiments, the intertransfusion, tho’ ingeniously carried out to a large extent never amounted to anything like a replacement of the circulatory medium of one animal by that of another & even in the partial replacements which took place, the fibrin of the blood was to a large extent excluded.² These facts of themselves should prevent us from yielding to M^r. Galton too readily even if we did not take into consideration the facts that the gemmules at any moment existing in the blood might be insignificant in number in proportion to those constantly being poured into the circulation & dormant in the tissues & that of the gemmules fibrin might be a conveyer. I am led to the conclusion that the various operations of Growth, Nutrition, Repair & Reproduction are carried on by the same agents & are essentially similar processes. These agents are the gemmules of your hypothesis. I hold that tissues are composed of gemmules which in the performance of their functions become partially exhausted & carried chiefly in the higher animals by the lymphatic circulation into the blood, these to be brought within the reach of nutriment & to be purified in glands & finally restored by the systemic capillaries to their appropriate places. At certain times aggregations of these gemmules are secreted from the blood by the testes as spermatozoa collect in the ovary as ova & are effused at the seats of injuries as the elements of repair. You can now see how, on this view, insignificant in proportion would be the number of the gemmules which could be conveyed from one animal to another by intertransfusion, how they would be incorporated with the living being & probably lose their distinct character. Within the bounds of a letter which I, a stranger, could venture to ask you to read, I could not give the reasons,—medical, surgical, Physiological & pathological—which have led me to the above conclusions nor point out the numerous facts which are explained on the above hypothesis. Nor could I within such limits dwell upon the reasons which lead me to the conclusion that fibrin is rich in gemmules & that in all probability the fibrinogen & fibrinoplastin of the chemists are but illusory products of german laboratories.³ When I have completed such researches as I can make without experiment I hope to throw more light on the subject.

I remain, Sir | yours very truly | George John Wilson