HISTORICAL SKETCH 449 



tered through M. Lecoq'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 new species is "a regular, 

 not a casual phenomenon," or, as Sir John Herschel expresses it, 

 "a natural in contradistinction to a miraculous process." 



The third volume of the "Journal of the Linnean Society" con- 

 tains 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. 



Von Baer, toward whom all zoologists feels so profound a re- 

 spect, expressed about the year 1859 (see Prof. Rudolph Wagner, 

 "Zoologisch-Anthrppologische Untersuchungen," 1861, s. 51) his 

 conviction, chiefly grounded on the laws of geographical distribu- 

 tion, that forms now perfectly distinct have descended from a 

 single parent-form. 



In June, 1859, Professor Huxley gave a lecture before the Royal 

 Institution on the "Persistent Types of Animal Life." Referring to 

 such cases, he remarks, "It is difficult to comprehend the mean- 

 ing of such facts as these, if we suppose that each species of ani- 

 mal and plant, or each great type of organization, 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 opposed 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 modifica- 

 tion which living beings have undergone during geological time is 

 but very small in relation to the whole series of changes which 

 they have suffered." 



In December, 1859, Dr. Hooker published his "Introduction 

 to the Austrahan Flora." In the first part of this great work he 

 admits the truth of the descent and modification of species, and 

 supports this doctrine by many original observations. 



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

 1859, and the second edition on January 7, 1860. 



