XL] EVOLUTION IN BIOLOGY. 293 



tude of monads with which he peopled the world, 

 each is supposed to be the focus of an endless process 

 of evolution and involution. In the " Protogsea," 

 xxvi., Leibnitz distinctly suggests the mutability of 



species 



" Alii mirantur in saxis passim species videri quas vel in orbe 

 cognito, vel saltern in vicinis locis frustra quaeras. Ita " Cornua 

 Ammonis," quae ex nautilorum numero habeantur, passim et forma 

 et magnitudine (nam et pedali diametro aliquando reperiuntur) 

 ab omnibus illis naturis discrepare dicunt, quas praebet mare. Sed 

 quis absconditos ejus recessus aut subterraneas abyssos pervesti- 

 gavif? quam multa nobis animalia antea ignota offert novus orbis 1 

 Et credibile est per magnas illas conversiones etiam animalium 

 species plurimum immutatas." 



Thus, in the end of the seventeenth century, the 

 seed was sown which has, at intervals, brought forth 

 recurrent crops of evolutional hypotheses, based, more 

 or less completely, on general reasonings. 



Among the earliest of these speculations is that 

 put forward by Benoit de Maillet in his " Telliamed," 

 which, though printed in 1735, was not published 

 until twenty-three years later. Considering that this 

 book was written before the time of Haller, or Bonnet, 

 or Linnaeus, or Button, it surely deserves more respect- 

 ful consideration than it usually receives. For De 

 Maillet not only has a definite conception of the 

 plasticity of living things, and of the production of 

 existing species by the modification of their prede- 

 cessors ; but he clearly apprehends the cardinal maxim 

 of modern geological science, that the explanation of 

 the structure of the globe is to be sought in the 

 deductive application to geological phenomena of the 



