182 



THE GEOLOGIST. 



branches fell off in myriads, with fruits, and catkins, and seeds, they 

 formed a matted mass in the sluggish water. 



On the stumps of the decaying trees the ferns would grow, and I 

 have seen markings on a Sigillaria which induce me to believe this 

 was really the case ; and the hollow trees would form a safe retreat 

 for such wingless insects, snails, or lizards, as the forest possessed. 



Lest this should be thought a wholly anomalous state of things, 

 we have, as an instance, the mangrove swamps of tropical countries, 

 where, in the saltwater lagoons, whole forests of trees grow, among 

 whose roots fish and Crustacea find protection, and sea-shells are 

 abundant. A species of oyster is commonly attached to the stems 

 and the submerged branches. And if the TJnio of the coal must be 

 regarded as an TJnio, there are even kinds of this genus which live in 

 these putrid swamps. 



For it must not be supposed that the trees grew in an open sea. 

 Shallow tracts, shut out from the main ocean by spits of sand and 

 sandbanks, and scarcely, if at all, subject to tides, are the state of 

 things that prevail in many a lagoon now ; and in all probability 

 such was the case in the coal epoch. In such localities it might be 

 expected that we should find creatures admirably adapted to their 

 habitation, but unlike the ordinary denizens of sea or lake. The 

 quantity of decaying vegetation would give a black colour to the 

 mud, and coal shales are very black indeed : occasional currents 

 would bring sand from seaward, and sandstones are common things 

 in the coal-formation. If the ocean got free entry tor a while, we 

 should have colonies of true sea animals (the Goniatites and Avicula 

 before mentioned), and such do every now and then occur. But the 

 ordinary inhabitants of these delightful muddy creeks, half smothered 

 in a thick forest of water-loving plants, would be the shells and 

 Crustacea suited to the locality, i. e., the Anthracosia or TJnio and the 

 Lirnulus. Crowds of minute water-fleas (Gypris and Cy there), such 

 as live in stagnant waters now, are found in the coal-measures. 

 Thousands of worms, of all sizes, burrowed in the silt, and revelled 

 in the feast of fat things that were putrifying there. 



I believe this picture gives the true aspect of the dank and lux- 

 uriant vegetation, floimshing in a sullen steaming atmosphere heavy 

 with miasmatous vapours ; uncheered by the song of birds, scarcely 

 musical with the hum of insects, and varied by no flowers, no trees 

 yielding fruit, whose seed was in itself ! Such a habitation was not fit 

 for man — not even for the quadrupeds he delights to call his own. 

 1 1 was the ground-plan and first outline only of a picture, to be filled 

 up during succeeding geologic times, and exquisitely finished before 

 man was placed upon the earth. 



AYhat effect must all this mass of vegetation have produced on the 

 Burrounding air and water ? Plants, we know, are chiefly formed of 

 carbon, taken into their substance from the air and water, under the 

 form of carbonic acid. They have the power of secreting the car- 

 bon from it, and they set free the oxygen for the use of animals. 

 So fchat an atmosphere in a confined spot is actually purer — more 



