Evolution of Evolution-Theory. 239 



(2) Experiment and observation as to the causes of 

 variations. 



(3) Experiments on the influence of surroundings 

 (see Semper, &c.). 



(4) Experiments on the influence of function (see 

 H. de Varigny's Experimental Evolution; Arbuthnot 

 Lane on the Anatomy of the Shoemaker]. 



(5) Experiments on amphimixis (see the records of 

 the Breeders and Cultivators). 



(6) Experiments on heredity (e.g. Cossar Ewart on 

 Telegony). 



(7) Experimental Embryology (e.g. the work of Roux, 

 Hertwig, Driesch, Herbst, Wilson, &c.). 



(8) Experimental Psychology (e.g. Lloyd Morgan on 

 chicks, &c.). 



(9) Experimental Bionomics (e.g. Stahl on snails). 



As to the mood in which this work should be done 

 and it will require centuries we can find no finer ex- 

 pression than Mr. Bateson has given in the preface to 

 his Materials for the Study of Variation. 



He heads his work with the familiar words: "All 

 flesh is not the same flesh; but there is flesh of men, 

 another flesh of beasts, another of fishes, and another 

 of birds", and says, "I have there set in all reverence 

 the most solemn enunciation of the problem that our 

 language knows. The priest and the poet have tried 

 to solve it, each in his turn, and have failed. If the 

 naturalist is to succeed he must go very slowly, making 

 good each step. He must be content to work with 

 the simplest cases, getting from them such truths as 

 he can; learning to value partial truth, though he cheat 

 no one into mistaking it for absolute or universal truth; 

 remembering the greatness of his calling, and taking 

 heed that after him will come Time, that ' author of 

 authors', whose inseparable property it is ever more 

 and more to discover the truth, who will not be de- 

 prived of his due," 



