VIII DARWINISM AND HOLISM 203 



an organ of touch or taste. Above all, there is the difficulty, 

 one might almost say the impossibility, of understanding 

 organic Evolution, if its advance depends upon mere for- 

 tuitous variations in reproduction, and remains uninfluenced 

 by the work, the experience, the learning through trial and 

 error and the consequent modifications of the individuals 

 which compose a race or species. While it is admitted 

 and intelligible that mere artificial and singular modifica- 

 tions, such as cutting off the tails of dogs or sheep continu- 

 ously for thousands of years, will have no germinal and no 

 hereditary effect, the case may apparently be quite different 

 with modifications which are due to the frequent or constant 

 activity of the animal, and which register the routine of 

 its life. Such modifications are far more intimate to the 

 animal organism, and may in the course of time produce 

 such a deep impression on the body-cells as to penetrate to 

 and reach even the germ-cells, and register a change there 

 which leads thereafter to hereditary and apparently spon- 

 taneous variation. 



Apart from Weismann's extreme doctrine of germinal 

 isolation, which even he by implication appears to have 

 found untenable, there is nothing in principle directly nega- 

 tiving such an assumption, and it does render intelligible 

 the progressive evolution and specialisation of bodily organs 

 which on any other assumption it is most difficult to under- 

 stand. The absence of direct experimental evidence in sup- 

 port of this view is not a fatal objection. The laboratory 

 of Nature is very different from that of experimental re- 

 search. Life has not been made in the latter but was made 

 in the former. The slow intimate operations extending over 

 thousands and even millions of years, such as brought about 

 most of the organic species of which we know, are not 

 on a par with our latter-day researches in experimental 

 evolution. With all our chemical knowledge we can yet 

 never hope to rival in our laboratories the results which 

 Nature has through the countless ages achieved, say, in 

 the crucible of the geological record. Still less can we 

 hope to achieve through biological experiments in the labora- 



