Number of Animals in Geological Times. 365 



doubt as to the final result ; we may confidently await the time 

 when the glory of the wonderful order of creation shall be fully 

 revealed to us, and this may stimulate us to renewed efforts, 

 since success depends entirely upon our own exertions. 



The geographical distribution of animals only began to be 

 studied long after systematic zoology had made considerable pro- 

 gress, but even to this day the limits of the faunse are nowhere 

 circumscribed with any kind of precision, the principles upon 

 which they might be determined are in many respects question- 

 able, and a large number of animals are daily described without 

 any reference to their natural distribution upon the earth ; though 

 much has already been done since Buffon to place this branch of 

 our knowledge upon a better foundation, and especially to ascer- 

 tain the laws regulating the geographical distribution of certain 

 classes and families considered isolatedly. The point which now 

 requires particular attention, is the combination of these differ- 

 ent types within definite regions, and their common circumscrip- 

 tion within natural zoological provinces. This study would be 

 particularly important with reference to the comparison of the 

 local faunae of former geological periods with those of the pre- 

 sent creation ; but since the latter even are comparatively little 

 known, we must be satisfied to wait for the time when thorough 

 comparisons shall be possible between the local faunae of each 

 and all geological periods inter se, and with those of other 

 periods. 



In closing this digression, I may sum up my criticism upon 

 palseontological investigations by saying, that any generalization 

 respecting the succession of organized beings which is not based 

 upon materials in which the synchronism and succession of spe- 

 cies and their geographical distribution are not duly considered, 

 and in which the identification of species is not made with refer- 

 ence to sound zoological principles, with due regard to the equal 

 limitation of genera, and also with reference to our improved 

 classifications in zoology, is not fit to be trusted. All species 

 taken into consideration should undergo a revision with reference 

 to their chronology, their topography, and their zoology ; and in 

 the last point of view, the range and natural limitation as well as 

 identity of the species, their generic affinities and their zoological 

 classification, should be equally tested. 



Returning now to the main subject of this paper, I have 

 further to say, that the very fact that certain stratified rocks, 

 even among the oldest formations, are almost entirely made up 

 of fragments of organized beings, should long ago have satisfied 

 the most sceptical that both animal and vegetable life was as 

 active and profusely scattered upon the whole globe, at all times and 

 during all geological periods, as it is now. No coral reef in the 

 Pacific contains a larger amount of organic debris than some of 



