HEREDItY BAOTESON. 373 



Way about. When the facts of genetic discovery become familiarly 

 known to biologists and cease to be the preoccupation of a few, as 

 they still are, many and long discussions must inevitably arise on 

 the question, and I offer these remarks to prepare the ground. I 

 ask you simply to open your minds to this possibility. It involves 

 a certain effort. We have to reverse our habitual modes of thought. 

 At first it may seem rank absurdity to suppose that the primordial 

 form or forms of protoplasm could have contained complexity 

 enough to produce the divers types of life. But is it easier to 

 imagine that these powers could have been conveyed by extrinsic 

 additions? Of what nature could these additions be? Additions of 

 material can not surely be in question. We are told that salts of 

 iron in the soil ma}'^ turn a pink hj^drangea blue. The iron can not 

 be passed on to the next geenration. How can the iron multiply 

 itself? The power to assimilate the iron is all that can be trans- 

 mitted. A disease-producing organism like the pebrine of silkworms 

 can in a very few cases be passed on through the germ cells. Such 

 an organism can multiply and can produce its characteristic effects 

 in the next generation. But it does not become part of the invaded 

 host, and we can not conceive it taking part in the geometrically 

 ordered processes of segregation. These illustrations may seem too 

 gross ; but vrhat refinement will meet the requirements of the problem, 

 that the thing introduced must be, as the living organism itself is, 

 capable of multiplication and of subordinating itself in a definite 

 system of segregation? That wdiich is conferred in variation must 

 rather itself be a change- — ^not of material but of arrangement, or 

 of motion. The invocation of additions extrinsic to the organism 

 does not seriously help us to imagine how the power to change can 

 be conferred, and if it proves that hope in that direction must be 

 abandoned, I think w^e lose very little. By the rearrangement of 

 a very moderate number of things we soon reach a number of possi- 

 bilities practically infinite. 



That prihiordial life may have been of small dimensions need not 

 disturb us. Quantity is of no account in these considerations. 

 Shakespeare once existed as a speck of protoplasm not so big as a 

 small pin's head. To this nothing was added that would not equally 

 well have served to build up a babboon or a rat. Let us consider 

 how far we can get by the process of removal of what we call 

 " epistatic " factors, in other words, those that control, mask, or sup- 

 press underlying powers and faculties. I have spoken of the vast 

 range of colors exhibited by modern sw^eet peas. There is no ques- 

 tion that these have been derived from the one wild bicolor form by 

 a process of successive removals. When the vast range of form, 

 size, and flavor to be found among the cultivated apples is con- 

 sidered, it seems difficult to suppose that all this variety is hidden 



