308 J. G. Goodchild—Formation of Coal-seams. 
This conclusion is largely supported by the fact that Maclure and 
other Arctic explorers actually found remains of some fossilized trees 
of species still living in North America in some of the islands of 
the Arctic Sea east of the River Mackenzie. These trees were 
rooted in the ground and in sité, and grew therefore very far to the 
north of the present range of trees in the New World. 
The reasoning I have ventured to adduce is based upon empirical 
evidence. If, as it seems to me, it is well founded, then it follows 
that the circulation of ocean currents in the Northern Hemisphere 
must have been entirely different from what it is now, since there 
was a barrier preventing the outgoing Arctic current from passing 
through Bering’s Straits. Such a change must have materially 
altered the climate. 
Secondly, the climate must have been very largely modified over 
the whole of Northern Asia in another and more direct way ; for the 
north winds which are now so keen and killing, since they come 
straight from the great northern reservoir of ice which is never at 
a higher temperature than 82°, would then come from a land of grass 
and trees, and be correspondingly softened. This would have a very 
great effect upon the Siberian climate in the direction of making it 
consistent with the Mammoth, the Horse, and the Bison finding food 
and shelter in the area between Alaska and Northern Asia. Pro 
tanto this is a solution of the question of how to account for a mild 
climate in these high latitudes. It does not, however, exhaust the 
preblem, and other causes remain, which perhaps you will let me 
discuss on another occasion. 
TV.—On some Mops oF Formation oF Coat-SEAMs. 
By J. G. Goopcnirp, F.G.8., H.M. Geol. Survey. 
(Based upon a paper read before the Royal Physical Society, Edinburgh, on the 
17th April, 1889.) 
HE commonly-received theory that most coal-seams represent 
_ vegetable matter that has grown and has been entombed on 
the spot has never been received by all geologists with quite that 
measure of satisfaction that has been accorded to other theories of 
the same general nature. It has been felt again and again that the 
explanation referred to might be true enough for certain cases; but 
that in others it failed to account satisfactorily for all the pheno- 
mena. It involved too many complications—too nice an adjustment 
of the rate of growth of the vegetation to the rate of subsidence and 
of sedimentation—too much straining of the theory in question 
generally—to be accepted unhesitatingly by those accustomed to 
judge of such facts for themselves. That certain beds of coal have 
been formed by the growth of vegetation on the spot no reasonable 
person can doubt: the only question is whether that is true of every 
coal-seam. Many competent observers have thought it is not; and 
the number of those who are dissatisfied with the view set forth in 
most text-books is certainly on the increase. Mr. W. 8. Gresley, 
and several other geologists, have lately advanced good arguments in 
favour of other views, which many are disposed to accept as correct. 
