14 THE FOUNDATIONS OF THE 'ORIGIN OF SPECIES.' 



sentence of the Sketch, which we saw in its first rough 

 form in the Note Book of 1837, closely resembles the final 

 sentence of the ' Origin,' much of it being identical. The 

 1 Origin ' is not divided into two " Parts," but we see traces of 

 such a division having been present in the writer's mind, in 

 this resemblance between the second part of the Sketch and 

 the final chapters of the ' Origin.' That he should speak * of 

 the chapters on transition, on instinct, on hybridism, and 

 on the geological record, as forming a group, may be due to 

 the division of his early MS. into two parts. 



Mr. Huxley, who was good enough to read the Sketch at 

 my request, while remarking that the " main lines of argu- 

 ment" and the illustrations employed are the same, points 

 out that in the 1844 Essay, " much more weight is attached to 

 the influence of external conditions in producing variation, 

 and to the inheritance of acquired habits than in the 

 ' Origin.' " 



It is extremely interesting to find in the Sketch the first 

 mention of principles familiar to us in the ' Origin of Species.' 

 Foremost among these may be mentioned the principle of 

 Sexual Selection, which is clearly enunciated. The important 

 form of selection known as " unconscious," is also given. 

 Here also occurs a statement of the law that peculiarities 

 tend to appear in the offspring at an age corresponding to 

 that at which they occurred in the parent. 



Professor Newton, who was so kind as to look through the 

 1844 Sketch, tells me that my father's remarks on the migra- 

 tion of birds, incidentally given in more than one passage, 

 show that he had anticipated the views of some later writers. 



With regard to the general style of the Sketch, it is not 

 to be expected that it should have all the characteristics of 

 the ' Origin,' and we do not, in fact, find that balance and 

 control, that concentration and grasp, which are so striking 

 in the work of 1859. 



* ' Origin,' Introduction, p. 5. 



