278 Britain's Heritage of Science 



into the workings of Heredity and we are acquiring a new 

 conception of the individual. The few years which have 

 elapsed since men's attention was redirected to the principles 

 first enunciated by the Abbot of Brunn have seen a School 

 of Genetics arise at Cambridge, and an immense amount of 

 practical experiment on inheritance has also been done in 

 France, Holland, Austria, and especially in the United States. 

 As the work has advanced new ideas have arisen and earlier 

 formed ideas have had to be abandoned; this must be so 

 with every advancing science. But it has now become 

 clear at any rate to some competent authorities that 

 mutations occur, and occur especially in cultivated species; 

 and that these mutations may breed true seems now to 

 be established. In wild species also they apparently occur, 

 but whether they are as common in wild as in cultivated 

 species remains to be seen. If they are not, in my opinion, 

 a most profitable line of research would be to endeavour to 

 determine what factor exists in cultivation which stimulates 

 mutation. 



To what extent Darwin's writings would have been 

 modified had Mendel's work come into his hands we can 

 never know. He carefully considered the question of 

 mutation, or as they called it then, saltation, and as time 

 went on, he attached less and less importance to these 

 variations as factors in the origin of species. Ray Lan- 

 kester has recently reminded us that Darwin's disciple and 

 expounder, Huxley, " clung to a little heresy of his own as 

 to the occurrence of evolution by saltatory variation," and 

 there must have been frequent and prolonged discussion on 

 the point. That " little heresy " has now become the ortho- 

 doxy of a number of eager and thoughtful workers who have 

 been at times rather aggressive in their attacks on the 

 supporters of the old creed. 



The publication of " The Origin of Species " naturally 

 aroused immense opposition and heated controversy. But 

 Darwin, as we have said, was no controversialist. Huxley 

 wrote shortly after his death : 



" None have fought better, and none have been more 



fortunate, than Charles Darwin. He found a great truth 



trodden underfoot, reviled by bigots, and ridiculed by all 



