Permanence and Evolution. 105 



He also says (op. cit, p. 118): "The 

 absolute identity of chalk in Australia and in 

 Europe is a proof that there was absolute 

 identity in the formative conditions and the 

 constituent elements, but no proof whatever 

 that the two substances were formerly connected 

 by genesis. In like manner the similarity of 

 a plant or animal in Africa and Europe may 

 be due to a common kinship, but it may also 

 be due to a common history. It is indeed 

 barely conceivable that the history, from first 

 to last, would ever be so rigorously identical in 

 two parts of the globe as to produce complex 

 identical forms in both ; because any diversity 

 either in structure or external conditions may 

 be the starting point of a wide diversity in 

 subsequent development, and the case of organic 

 combinations is so far unlike the inorganic 

 that while only one form is possible to the latter 

 (chalk is either formed or not formed), many 

 forms are possible to organic elements owing to 



