108 Horner's Geological Address. 



twenty-one more Calamites are visible along the bank in the 

 space of twenty yards. 



This is the last instance stated of stems of plants found in 

 the strata perpendicular to the plane of stratification ; the 

 seventeen instances thus occurring in a vertical thickness of 

 4515 feet. 



Throughout the whole 7000 feet in the South Wales sec- 

 tion, and, if the limestones are, as is most probable, of fresh- 

 water origin, also throughout the 14,570 feet in the Nova 

 Scotia section, there appears to be no trace of any substance 

 of a marine character ; and from anything exhibited in the 

 composition of the beds, all might have. been deposited in 

 fresh water. It seems infinitely improbable, had the deposi- 

 tion taken place in a sea, that a series of accumulations of 

 this description, implying, be it observed, a vast duration of 

 time, with different depths and different qualities of sea-bot- 

 toms, should have taken place without a trace being discover- 

 able, either upon the surface of the submerged layers of ve- 

 getable matter, or in any part of the clays and sandstones 

 that lie upon them, of a marine animal or plant. It seems 

 no less improbable, that, in a sea skirting a shore, there 

 should be such an absence of agitation throughout so vast a 

 space of time, as to allow a tranquil deposit of layers of fine 

 detritus over a wide area, a spreading out of the leaves of 

 delicate plants in layers of clay and sand, like the specimens 

 in a herbarium, and a gradual and insensible passage, in many 

 instances, from one bed into another. Great as the North 

 American lakes are, I am not prepared to say that grave ob- 

 jections may not be urged against the probable existence of 

 such vast bodies of fresh water as would be of sufficient ex- 

 tent and depth to receive the beds of many coal-fields ; but 

 the absence of marine remains throughout vast depths of 

 strata in coal-fields is a remarkable fact, well deserving of the 

 most careful investigation. 



That the terrestrial vegetable matter from which coal has 

 been formed has in very many instances been deposited in 

 the sea is unquestionable, from their alternations with lime- 

 stones containing marine remains. Such deposits and alter- 

 nations in an estuary at the mouth of a great river are con^ 



