96 THEOLOGIANS AND NATURAL PHILOSOPHERS. 



Huxley quotes from the Protogaa (XXVI.) a pas- 

 sage which proves that Leibnitz also had his own 

 thoughts and observations upon the mutability of 

 species. He is speaking of the fossil Ammonites 

 related to the living Nautilus, and, after noting the 

 infinite variations in their shells, and the gradations 

 which are presented among these forms, says : 



" Some are surprised that there are to be seen everywhere in 

 rocks such objects as one might seek for in vain elsewhere in the 

 known world, or certainly, at least, in his own neighbourhood. 

 Such are the horns of Ammon (Ammonites), which are reckoned 

 a kind of Nautilus, although they are said to differ always both in 

 form and size, sometimes indeed being found a foot in diameter, 

 from all those animal natures which the sea exhibits. Yet who 

 has thoroughly searched those hidden recesses or subterranean 

 depths? And how many animals hitherto unknown to us has 

 a new world to offer? Indeed it is credible that by means of 

 such great changes (of habitat) even the species of animals are 

 often changed." 



His law of Continuity was in another passage 

 expressed as follows showing conclusively that he 

 held very positive views as to the evolution of life : 



"All advances by degrees in Nature, and nothing by leaps, 

 and this law as applied to each, is part of my doctrine of Con- 

 tinuity. Although there may exist in some other world species 

 intermediate between Man and the Apes, Nature has thought it 

 best to remove them from us, in order to establish our superiority 

 beyond question. I speak of intermediate species, and by no 

 means limit myself to those leading to Man. I strongly approve 

 of the research for analogies ; plants, insects, and Comparative 

 Anatomy will increase these analogies, especially when we are 

 able to take advantage of the microscope more than at present." 



