16 HISTORICAL SKETCH. 



Geograph. Bot.," torn, i., p. 250), " Oa voit que nos rcchcrchcs sur la fixate 

 ou la variation ilc Tespece, nous conduiscnt dircctcment aux idecs emisea 

 par deux honiincs justcmcnt celebrcs, Geofifroy Saint-llilairc ct Goethe." 

 Some other passages, scattered through M. Lccoq's large work, make it a 

 little doubtful how far he extends his views on the modification of species. 



The " Philosophy of Creation " has been treated in a masterly manner 

 by the Rev. Baden Powell, in his "Essays on the Unity of Worlds," 1855. 

 Nothing can be more striking than the manner in which he shows that the 

 introduction of a new species is " a regular, not a casual phenomenon," or, 

 as Sir John llerschel expresses it, " a natural in contradistinction to a mi- 

 raculous process." 



The third volume of the Journal of the Linnean Sociehj contains 

 papers, read July 1, 1858, by Mr. Wallace and myself, in which, as stated in 

 the introductory remarks to this volume, the theory of Natural Selection is 

 promulgated by Mr. Wallace with admirable force and clearness. 



Yon Baer, toward whom all zoologists feel so profound a respect, ex- 

 pressed, about the year 1859 (see Prof. Rudolph Wagner, " Zoologisch-An- 

 thropologische Untcrsuchungen," 1861, s. 51), his conviction, chiefly grounded 

 on the laws of geographical distribution, that forms now perfectly distinct 

 have descended from a single parent-form. 



In June, 1859, Prof. Huxley gave a lecture before the Royal Institution 

 on the "Persistent Types of Animal Life." Referring to such cases, he re- 

 marks : " It is difficult to comprehend the meaning of such facts as these, if 

 we suppose that each species of animal and plant, or each great type of or- 

 ganization, was formed and placed upon the surface of the globe at long 

 intervals by a distinct act of creative power ; and it is well to recollect that 

 such an assumption is as unsupported by tradition or revelation, as it is op- 

 posed to the general analogy of Nature. If, on the other hand, we view 

 ' Persistent Types' in relation to that hypothesis which supposes the species 

 living at any time to be the result of the gradual modification of pre- 

 existing species — a hypothesis which, though unproven, and sadly damaged 

 by some of its supporters, is yet the only one to which physiology lends any 

 countenance ; their existence would seem to show that the amount of modi- 

 fication which living beings have undergone during geological time is but 

 very small in relation to the whole scries of changes which they have suf- 

 fered." 



In December, 1859, Dr. Hooker published his " Introduction to the Aus- 

 tralian Flora." In the first part of this great work he admits the truth of 

 the descent and modiCcatiou of species, and supports this doctrine by many 

 original observations. 



The first edition of this work was published on November 24, 1850, and 

 the second edition on January 7, 18G0. 



