/4 Antiqidty uf the Human Race. 



sediment including entire shells, both terrestrical and aquatic, and 

 also for the denudation which the entire mass of stratified drift has 

 undergone, portions having been swept away, so that what remains 

 of it often terminates abruptly in old river cliffs, besides being 

 covered by a newer unstratified drift. To explain these changes I 

 should infer considerable oscillations of the land in that part of 

 France — slow movements of upheaval and subsidence, deranging 

 but not wholly displacing the course of the ancient rivers. Lastly, 

 the disappearance of the Elephant, Khinoceros, and other genera 

 of quadrupeds now foreign to Europe implies, in like manner, a 

 vast lapse of ages, separating the era in which the fossil implements 

 were frame i and that of the invasion of Gaul by the Romans. 



Among the problems of high theoretical interest which the recent 

 prograss of Geology and Natural History has brought into notice, 

 no one is more prominant, and, at the same time, more obscure, 

 than that relating to the origin of species. On this difficult and 

 mysterious subjects a work will ^-^ery shortly appear, by Mr. Charles 

 Darwin, the result of twenty years of observation and experiment 

 in Zoology, Botany and Geology, by which he has been led to the 

 conclusion that those powers of nature which give rise to races and 

 permanent varieties in animals and plants, are the same as those 

 which in much longer periods, produce species, and. in a still longer 

 series of ages, give rise to differences of generic rank. He appears 

 to me to have succeeded, by his in^'^estigations and reasonings, to 

 have thrown a flood light on many classes of phenomena, connected 

 with the aifinitie?, geographical distribution, and geological suc- 

 cession of organic beings, for which no other hypothesis has been 

 able, or has even attempted, to account. 



Among the communications sent in to this Section, I have re- 

 ceived from Dr. Dawson, of 3Iontreal, one confirming the discovery 

 which he and I formsrly announced, of a land shell, or pupa, in 

 the coal formation of Nova Scotia. When we contemplate the vast 

 series of formations intervening between the Tertiary and Carbo- 

 niferous Strata, all destitute of air-breathing mollusca, at least 

 of the terrestrial class, such a discovery affords an important illus- 

 tration of the extreme defectiveness of the o-eolosrical records. It 

 has always appeared to me that the advocates of progressive deve- 

 lopment have too much overlooked the imperfection of these records, 

 and that, consequ3ntly a large part of the generalization in which 

 they have indulged in regard to the first appearance of the different 

 classes of animals, especially of air-breathers, will have to be modi- 



