182 CRITIQUES AND ADDRESSES. [ix. 



parallelism. In other words, certain forms of life in 

 one locality occur in the same general order of suc- 

 cession as, or are homotaxial with, similar forms in the 

 other locality. 



3. Homotaxis is not to be held identical with synchro- 

 nism without independent evidence. It is possible that 

 similar, or even identical, faunae and florae in two different 

 localities may be of extremely different ages, if the term 

 " age " is used in its proper chronological sense. I stated 

 that "geographical provinces, or zones, may have been as 

 distinctly marked in the Palaeozoic epoch as at present ; 

 and those seemingly sudden appearances of new genera 

 and species, which we ascribe to new creation, may be 

 simple results of migration." 



4. The opinion that the oldest known fossils are the 

 earliest forms of life has no solid foundation. 



5. If we confine ourselves to positively ascertained 

 facts, the total amount of change in the forms of animal 

 and vegetable life, since the existence of such forms is re- 

 corded, is small. When compared with the lapse of time 

 since the first appearance of these forms, the amount 

 of change is wonderfully small. Moreover, in each great 

 group of the animal and vegetable kingdoms, there are 

 certain forms which I termed PERSISTENT TYPES, which 

 have remained, with but very little apparent change, 

 from their first appearance to the present time. 



6. In answer to the question "What, then, does an 

 impartial survey of the positively ascertained truths of 

 palaeontology testify in relation to the common doctrines 

 of progressive modification, which suppose that modifi- 

 cation to have taken place by a necessary progress from 

 more to less embryonic forms, from more to less gene- 

 ralized types, within the limits of the period represented 

 by the fossiliferous rocks?" I reply, " It negatives these 

 doctrines ; for it either shows us no evidence of such 



