RELATION OF BIOLOGY TO GEOLOGICAL INVESTIGATION. 291 



author has ever published these propositions in the exact form in 

 which they arc here presented, but I have formulated them from the 

 published utterances of numerous authors and from my personal recol- 

 lections of an active participation in geological work during a number 

 of years immediately preceding the great revolution in methods of bio 

 logical thought and investigation which has been referred to. In stat- 

 ing these propositions reference is necessarily made to the divisions and 

 subdivisions of the table on page 2S<>, representing the geological scale 

 for 1840, and to the paragraphs preceding and following it. These 

 propositions are: 



(1) That every species of animals and plants, both living and extinct, was specially 

 created, and that they are, and always have been, immutable. That genera, and 

 also the higher groups into w -Inch both the animal and vegetable kingdoms are sys- 

 tematically divisible, are categories of creative thought, and that they also are im- 

 mutable. 



(2) That although secular extinction of certain species, and even genera, occurred 

 during everj stage of the geological scale, at the close of each stage, except the 

 Tertiary, all life upon the earth was simultaneously destroyed, and that at the close 

 of each substage life was at least in large part destroyed. 



(3) That, at the close of each stage coincidently with, and the divinely ordained 

 instrument of, the complete extinction of life there was a universal physical catas- 

 trophe, and that the close of each substage was, at least in part, physically catastro- 

 phic. 



(4) That all life for each successive stage was created anew. 



(5) That the life of each stage embraced specially ordained generic, or more gen- 

 eral, types which were distinctive of and peculiar to it, and that their distribution 

 was world-wide. 



(8) That there was a special ordination of characteristic types for each substage, 

 which received world-wide and simultaneous distribution within its narrow time 

 limits. 



(7) That no identical and few similar, specific forms were created for any two or 

 more stages. 



(8) That the world-wide distribution of the distinctive types of animals and plants 

 which were ordained to characterize any stage or substage was effected in connec- 

 tion with the act by which their respective faunas and floras were created; or that 

 in the case of species not having a world-wide distribution the typical integrity of 

 faunas and floras was preserved by the introduction of representative, that is, closely 

 similar, but distinct species. 



(9) That by creative design the average biological rank of each new creation was 

 higher than that of the next preceding one. 



(10) That upon the fossilizable parts of the animals and plants which were cre- 

 ated for each stage, and upon those designed to characterize each substage, was 

 impressed not only their own structural features, but recognizable evidence of their 

 chronological ordination. 



These propositions represent only those views of the pioneer geolo- 

 gists which pertain to biological geology. Other views which were 

 held by them are unassailable, eyen in the light of the present advance 

 of science, and their biological views are not introduced here for the 

 purpose of disparagement, but to show that they gave origin to certain 

 erroneous methods which are in part retained as an inheritance by 



