12G 



THE AMERICAN NATURALIST [Vol. L 



5. Wright, Sewall. 1914. Unpublished MS. 



6. Pearson, Karl. Phil Magazine, July, 1900, Vol. L, 157-175. 



7. Elderton W. P. BiometriJca, 1901, Vol. 1, 155-163. 



8. Harris, J. Arthur. American Naturalist, Dec, 1912, 741-745. 



9. Bateson, Wm. Mendelian Principles of Heredity, University Press, 



1909. 



10. Fuehs, Ernst. Text-Book of Ophthalmology, translation by A. Duane, 

 4th edition. 



HUXLEY AS A MUTATIONIST 



Elsewhere I have pointed out that Galton 1 held with equal 

 firmness to continuity and discontinuity in variation, and that 

 the American horticulturist and botanist, Thomas Meehan, 2 held 

 clear mutationist conceptions which he supported by accurate ob- 

 servations of variations in many plants. It seems worth while 

 to add a note on the attitude of Huxley with regard to this ques- 



"Whenever Huxley expressed himself on this matter he usually 

 took occasion to say explicitly that he could see no reason why 

 variations should not be discontinuous as well as continuous, and 

 one of the few points on which he differed from Darwin was in 

 ascribing greater significance to such marked changes. Several 

 statements of his position in this matter are found in his volume 

 of essays entitled Darwiniana. 



Thus he says (p. 77) : 



Mr. Darwin's position might, we think, have been even stronger than 

 it is if he had not embarrassed himself with the aphorism " natura non 

 facit saltttm," which turns up so often in his pages. We believe, as we 

 have said above, that Nature does make jumps now and then, and a 

 recognition of the fact is of no small importance in disposing of many 



Elsewhere (pp. 34, 404) Huxley refers to the well-known Ancon 

 sheep, which originated from a single ram in the flock of a Mas- 

 sachusetts farmer named Seth Wight. The story of this breed 

 of sheep is told in a letter from Col. David Humphreys to Sir 

 Joseph Banks, then President of the Royal Society. 3 The farmer 

 kept a flock of 15 ewes and one ram on the banks of the Charles 

 River, at Dover, Mass., 16 miles from Boston. In 1791 a ram 



1 "Galton and Discontinuity in Variation/' Amee. Nat., 48: 697-699, 

 1914. 



2 "An Anticipatory Mutationist," Amer. Nat., 49: 645-648, 1915. 



3 Humphreys, D., 1813, "On a New Variety in the Breeds of Sheep," Phil. 

 Trans. Soy. Soc, 1813: 88-95. 



