97 



On Coral Beefs Present and Past. 



By Thomas Weight, M.D., r.E.S.E'4? , T.G.S. 



Modern Coeal Reefs. 



Introduction. — The remarks made by otir President, incident to 

 the recent visit of the Cotteswold Club to the fine old Coral 

 reef at Brown's Hill, near Stroud, suggested the following 

 communication,* in which I shall endeavour to bring within 

 the compass of a short paper the observations I have from 

 time to time made to our members, by way of explanation, 

 when the different Coral beds met with in our rambles over the 

 Cotteswolds have formed the subject of conversation. In doing 

 so, however, it will be necessary to introduce my remarks upon 

 the Coral reefs of the past with a brief resume of some of the 

 leading facts connected with the natural history of the Coral 

 formations of the present period, in order that the physical 

 conditions under which such structures are produced, and the 

 laws which appear to regulate the Polyp life of their builders, 

 may be better understood. 



That there are masses of rock many leagues in extent, founded 

 in the recesses of the ocean, and built up into gigantic structures, 

 from a hundred to two thousand feet in thickness, by the 

 secretions of Polyps, is a fact of deep interest to the nattu'alist, 

 and of great significance to the geologist, the study of which 

 affords him important data for reasoning on the operations of 

 these animals in former periods of the earth's history. It has 



* The substance of this paper was communicated to the Members of the Club at 

 the May-Hill Meeting, 13th June, 1866. 



