444 THE ORIGIN OF SPECIES 



each genus were created in an originally highly plastic condition, 

 and that these have produced, chiefly by intercrossing, but like- 

 wise by variation, all our existing species. 



In 1826 Professor Grant, in the concluding paragraph in his 

 well-known paper ("Edinburgh Philosophical Journal," vol. xiv. 

 p. 283) on the Spongilla, clearly declares his belief that species 

 are descended from other species, and that they become improved 

 in the course of modification. This same view was given in his 

 Fifty-fifth Lecture, published in the "Lancet" in 1834. 



In 1831 Mr. Patrick Matthew published his work on "Naval 

 Timber and Arboriculture," in which he gives precisely the same 

 view on the origin of species as that (presently to be alluded to) 

 propounded by Mr. Wallace and myself in the "Linnean Journal," 

 and as that enlarged in the present volume. Unfortunately the 

 view was given by Mr. Matthew very briefly in scattered passages, 

 in an appendix to a work on a different subject, so that it re- 

 mained unnoticed until Mr. Matthew himself drew attention to it 

 in the "Gardeners' Chronicle," on April 7, 1860. The differences 

 of Mr. Matthew's views from mine are not of much importance: 

 he seems to consider that the world was nearly depopulated at 

 successive periods, and then restocked ; and he gives as an alterna- 

 tive, that new forms may be generated "without the presence of 

 any mould or germ of former aggregates." I am not sure that I 

 understand some passages; but it seems that he attributes much 

 influence to the direct action of the conditions of life. He clearly 

 saw, however, the full force of the principle of natural selection. 



The celebrated geologist and naturalist. Von Buch, in his ex- 

 cellent "Description Physique des Isles Canaries" (1836, p. 147), 

 clearly expresses his belief that varieties slowly become changed 

 into permanent species, which are no longer capable of intercross- 

 ing. 



Rafinesque, in his "New Flora of North America," published 

 in 1836, wrote (p. 6) as follows: "All species might have been 

 varieties once, and many varieties are gradually becoming species 

 by assuming constant and peculiar characters;" but further on 

 (p. 18), he adds, "except the original types or ancestors of the 

 genus." 



In 1843-44 Professor Haldeman ("Boston Journal of Nat. Hist. 

 U. States," vol. iv. p. 468) has ably given the arguments for and 

 against the hypothesis of the development and modification of 

 species: he seems to lean toward the side of change. 



The "Vestiges of Creation" appeared in 1844. In the tenth and 

 much improved edition (1853) the anonymous author says (p. 



