BUrnSII ASSOCIATION MEETING. 
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use of iron \vas unknown, made n lon;^ sojourn in tliis region ; and I am re- 
minded ol' a large Indian mound wliieJi I saw in St. Simond's Island iu Gcorg-ia 
— a mound ten acres iu area, and having an average height of five feet, chieily 
composed of east-away oyster-shells, throughout vvhieli arrow-heads, stone-axes, 
and Indian pottery are dispersed. If the ueighljouring river, the Alatamaha, 
or the sea, which is at h:iud, should invade, sweep away, and stratify the con- 
tents of this mound, it might jjroducc a very analogous accumulation of human 
implements, unmixed, perhaps, witli human bones. Although the accomjiany- 
iug shells are of living species, I believe the antiquity of the xVbbeviUe and 
Amiens fliut-instruments to be great indeed if compared to the times of history 
or tradition. I consider the gravel to be of fluviatile origin, but I could de- 
tect nothing in the structure of its several parts indicating cataclysnud action; 
nothing that might not be due to such river-tloods as we have witnessed iu 
Scotland during the last half centuiy. It must have requuxd a long period for 
the wearing down of the chalk which supplied the broken flints for the forma- 
tion of so much gravel at various heights, sometimes one hundred feet above 
the present level of the Somme ; for the deposition of tine sediment, including 
entire shells, both terrestrial and aquatic ; aud also for the denudation which the 
entire mass of stratified tli-ift has undergone, portions having been swept away, 
so that what remains of it often terminal es abrujjtly in old river-cliffs, besides 
being covered by a newer unstratified drift. To explain Ihcse changes I should 
infer considerable oscillations in tlie level of the land in that part of France- 
slow movements of ujiheaval and subsidence, deranging, but not wholly dis- 
placing, the course of the ancient rivers. Lastly, the disappearance of the 
elephant, rhinoceros, and other genera of quadrupeds now foreign to Europe, 
implies, in like manner, a vast lapse of ages separating the era iu which the 
fossil implements were formed and that of the invasion of Gaul by the Romans. 
Among the problems of high theoretical interest wliich the recent progress of 
geology and natural history has brought into notice, no one is more prominent, 
and at the same time more obscure, than that relating to the origin of species. 
On tliis difficult aud mysterious subject a work will very slioilly appear by Mr. 
Charles Darwin, the result of twenty years of observation and experiment iu 
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, pro- 
duce species, and, in a still longer series of ages, give rise to differences of 
generic rank. He appears to me to have siicceeded, by his investigations and 
reasonings, to have throwm a flood of light on many classes of phenomena 
connected with the affinities, geographical distribution, and geological succes- 
sion of organic beings, for which no other hypothesis has been able, or has even 
attempted to account. Aiuong the comuiuuications sent into this section, I 
have received froni Dr. Dawson, of Montreal, one confirming tlie discovery 
whicli he and I formerly announced, of a land-shell, or pupa, in the Coal-forma- 
tion of Nova Scotia. When we contemplate the vast series of formations inter- 
vening between the tertiary and carboniferous strata, all destitute of air- 
breatliing moilnsea, at least of the terrestrial class, such a discovery affords an 
important illustration of the extreme defectiveness of our geological records. 
It has always appeared to me that the advocates of progressive development 
have too much overlooked the imperfection of these records, and that conse- 
quently a large part of the generalizations in w-hieh they have iiididged in 
regard to the first appearance of the different classes of ammals, especially of 
air-breathers, will have to be modified or abandoned. Nevertheless, that the 
doctrine of progressive development may contain in it the germs of a true 
theory, I am far from denying. The consideration of this question will come 
before you when the age of the white sandstcme of Elgin is discussed — a rock 
