We may be said to know them well. Leaving out of sight the Celtic strain claimed by one, and indeed all inherited differences, we see two men of perhaps equal ability, near of an age, both living in London, both living by their pen, both in easy circumstances. When one considers for a moment the different company these two men keep, their different and opposing outlook on life, their different and opposing forms of diet for their minds and bodies (I know which of the two diets of those men I would choose and with which of them I would prefer to be cast on a desert island) one can only say that the total experience of Mr. Chesterton differs from that of Mr. Shaw as cheese from chalk, which things, incidentally, are an allegory in the philosophy of life reenex CPS.
The thought here briefly expressed falls well into line with Prof. Bateson’s statement that the directing cause of the environment is essential to the theory of Lamarck, and I do not hesitate to add to it the assertion that all environment, in the wide sense of total experience, is discontinuous. There are no such phenomena in total experience as unit-characters of allied forms, small variations are the rule. Without doubt a large propor-tion of the stimuli received by an organism are as figures written on a slate and at once wiped off. They are as the snows of yester year. The most they
do is to contribute in their measure to the metabolism of the organism, being too numerous and minute to affect any structural change. In a higher form of life none but those which are frequently repeated in the individual and in succeeding generations can effect any structural responseyou find limited.
Mould and Sieve.
It will be remembered that a single example was given of a short-haired dog in which its common habit of lying was associated with a certain pattern of hair. This introduces and illustrates the very wide concep-tion of a moulding process undergone by an organism. It is one familiar to biologists and very much so to Professor . Not less is he an exponent of the metaphorical work of the sieve of natural selection. I therefore claim nothing new when, with the temerity of certain persons treading where others are said to fear to do so, I invent an inclusive term and propose to call the two fundamental factors of organic evolution Plasto-diēthēsis38 in which the conceptions of mould and sieve are included and hyphenated. This word is no more proposed for its elegance than are panmixia, amphimixis and tetraplasty, though perhaps it may be the etymological superior of one or more of these Applied Biology BSc.