96 PROCEEDINGS OF THE COTTESWOLD CLUB 



During the last fifty years there has been considerable 

 discussion as to the origin of coal, and several papers on 

 this subject have appeared in the Club's Proceedings. 

 The vegetable origin of coal is, of course, established 

 without doubt, but the nature of this vegetation is not 

 even now accurately ascertained. For some years coal 

 seams were supposed to have originated from the sub- 

 mergence of forests, but more recent research seems to 

 point to aquatic vegetation, more in the nature of bogs 

 than forests. 



With the Coal Period the Palaeozoic series of rocks 

 come to an end, and this end was brought about bv 

 physical disturbance on a very grand scale. Instead of 

 there being a continuous series of horizontal beds 

 deposited one over the other in regular sequence, the 

 Palaeozoic system of rocks became tilted up, and it was 

 not till after a long lapse of time that these forces sub- 

 sided and the process of rock building continued. The 

 debris which formed the Permian and Trias systems was 

 then deposited over the upturned edges of the Palaeozoic 

 rocks. As to what went on during this great interval we 

 are but little better informed than we were 50 years ago. 

 All we know is that when the forces of disturbance ceased 

 a new order of things was introduced with the advent of 

 the Secondary Period. Most of the life of Palaeozoic 

 days hai disappeared, and new forms appeared in the 

 Permian and Trias rocks, which lie at the base of the 

 Secondary series, this life including Marsupials, Mam- 

 malia, and numerous Rcptilia, and among the latter is the 

 Thecodonto-.saurus discovered in the Keuper beds near 

 Bristol. 



Resting on the uppermost beds of the Trias are a very 

 interesting series of strata which have been the subject of 

 much discussion at the Clul) meetings, the question in 

 dispute being to define where the Trias system ends and 



