J. Marcou — Jura and Neocornian of Arkansas, etc. 197 



Art. XXIII. — Jura and Neocornian of Arkansas, Kansas, 

 Oklahoma, New Mexico and Texas ; by Jules Marcou. 



Historic geology, or stratigrapliic classification, is a very 

 difficult and at the same time a most important part of the 

 history of our globe. Without exact classification, all becomes 

 confusion, geologic periods are confounded, and we are con- 

 fronted by the same sort of errors that would occur if some 

 historian were to place the time of Cromwell after the time of 

 Washington. 



In all other sciences, like chemistry, physics, anatomy, etc. 

 each new fact can be verified in laboratories, after a period of 

 time relatively short. Not that criticism, and strong and even 

 passionate opposition, are not found in these sciences ; we re- 

 member well the protest against the experiments made to dis- 

 prove spontaneous generation. It required much persistency 

 and courage on the part of Pasteur to maintain the truth he 

 had discovered. The chemist Berthelot published in the 

 Revue Scientifique some incomplete investigations of the late 

 Claude Bernard, which he found in loose notes after the lat- 

 ter's death, without even taking the polite precaution to make 

 known to Pasteur his intention of attacking his observations on 

 the non-existence of spontaneous generation. Numerous dis- 

 cussions followed at the meetings of the Academy of Science 

 of the French National Institute, until Pasteur, excited by the 

 incessant attacks of two adversaries, bravely turned towards 

 them and said to one, u Savez-vous ce qui vous manque? vous 

 ignorez l'art d'observer ;" and to the other, " Et vous, celui de 

 raisonner."* 



The controversy against my observations on the geology of 

 Texas, the Indian Territory and New Mexico, has lasted much 

 longer than the opposition made against Pasteur, for it is now 

 forty-four years since I made them and they have been and are 

 still the subject of constant criticism. 



In science, discussion must be based on the observation of 

 facts; in geology, these observations must be made on the 

 ground and at the precise locality under discussion. For years 

 the two localities discussed were not only far distant from 

 civilization, but also situated in a part of the country which, 

 on account of hostile Comanches, Kiowas and Apaches, it 

 was impossible to visit without a large military escort. Con- 

 sequently my contradictors discussed my observations without 

 a practical knowledge of the stratigraphy ; and with a want of 



* Discours de M. Joseph Bertrand, directeur de l'Academie Francais, seance du 

 28 Janvier, 1897. 

 Am. Jour. Sot.— Fourth Series, Yol. IT, No. 21.— Sept., 1897. 

 14 



