tiii HISTORICAL SKETCH. 



The Hon. and Rev. W. Herbert, afterward Dean ot Man- 

 chester, in the fourth volume of the " Horticultural Trans- 

 actions," 1822, and in his work on the " Amaryllidaceae " 

 (1837, pp. 19, 339), declares that " horticultural experiments 

 nave established, beyond the possibility of refutation, that 

 botanical species are only a higher and more permanent class 

 of varieties." He extends the same view to animals. The 

 dean believes that single species of each genus were created 

 in an originally highly plastic condition, and that these have 

 produced, chiefly by intercrossing, but likewise 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 pre- 

 cisely the same view on the origin of species as that (pres- 

 ently 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 remained 

 unnoticed until Mr. Matthew himself drew attention to it 

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

 ferences 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 alternative, 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 pas- 

 sages ; 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 

 excellent " Description Physique des Isles Canaries " (1836, 

 p. 147), clearly expresses his belief that varieties slowly be- 

 come changed into permanent species, which are no longer 

 capable of intercrossing. 



Rafinesque, in his " New Flora of North America," put* 



