156 EVOLUTION AND DOGMA. 



Davidson's exhaustive researches on the brachio- 

 pods of the English formations, lead him to the same 

 conclusions as those arrived at by Barrande after his 

 prolonged studies of the trilobites and cephalopods 

 of Bohemia, viz., that there is not the slightest 

 trace of any tendency towards development on the 

 part of the species examined. 



Similar testimony is given by Mr. Williamson 

 regarding fossil plants. After forty years of patient 

 study of the vegetable remains of different geolog- 

 ical ages, he does not hesitate to affirm that the ferns 

 whose imprints are of such frequent occurrence in 

 certain strata of the Carboniferous Age, have re- 

 tained their essential characteristics until the present 

 time. For, if we compare those which now abound 

 in our forests with those which gave beauty to the 

 landscape in Paleozoic time, we find that they have 

 neither advanced nor retrograded. 



It were easy to add to the list of persistent types 

 of animals and plants, of those, namely, which en- 

 dured unchanged during long geologic periods. I 

 might speak of the terebratulae and globigerinae 

 which take us back to the Cretaceous Period ; of 

 certain types of scorpions which flourished during 

 the Carboniferous Age and which are scarcely dis- 

 tinguishable from modern scorpions ; of the lingulae 

 and lingulellae which, appearing in the lower Silu- 

 rian rocks, have persisted practically unchanged 

 through all the grand climacterics of the world. 1 



1 For able and dignified discussions of the questions here 

 considered, see " Paleontologie et Darwinisme," by the eminent 

 Belgian geologist, Charles de la Vallee Poussin, in the " Revue 



