ANNIVERSARY ADDRESS OF THE PRESIDENT. H 



is the result of chemical action combined with a simultaneously acting 

 arranging molecular force, generally developed at temperatures below 

 the fusion or semi-fusion of rocks ; also that when we find rocks which 

 we know have been previously in a state of fusion, possessing a foli- 

 ated structure, this structure has been induced subsequently to their 

 solidification ; 3. That the arrangement of foliation may often be due 

 to the intrusion or approach of igneous rocks ; and 4. That there is 

 reason to suppose that the foliated rocks may be altered fossiliferous 

 strata, from their chemical composition, from the presence of certain 

 minerals, and on account of the changes known to take place in 

 other fossiliferous rocks. 



Notwithstanding certain points of agreement between the respective 

 authors of these papers, there is still such an amount of difference of 

 opinion amongst them as to make it desirable that more information, 

 based on careful and accurate observation in different districts, should 

 be obtained on the subject, before we can venture to say that any 

 satisfactory explanation of the many varied phsenomena connected 

 with the cleavage and foliation of rocks has been obtained. 



The paper by Mr. O. Westwood, entitled " Contributions to Fossil 

 Entomology," is one of great interest, and which, taken into consi- 

 deration with another paper to which I shall briefly allude, is of 

 importance in enabling us better to understand the progressive changes 

 of organic life, and to unravel some at least of the causes which have 

 led to the modifications of animal life during the different periods of 

 geological time. Not being an entomologist, I have no pretension 

 to speak about the details of the paper ; but I must at least call your 

 attention to the admirable execution of the plates by which it is 

 illustrated, and to the care which Mr. Westwood has bestowed on the 

 description of the different remains submitted to him for examination. 

 By far the largest portion of these numerous suites of fossil insects 

 were obtained by Messrs. Brodie and Willcox from the lower Purbeck 

 beds of Durdlestone B^y. They leave no doubt, whatever may have 

 been the nature of the climate which they are supposed to indicate, 

 that a vast assemblage of insect life must have existed in the imme- 

 diate vicinity of the spot where they were entombed and preserved. 

 This fact is peculiarly interesting when taken in connexion with the 

 discovery by Mr. Brodie of mammalian remains in some of the 

 members of the Purbeck formation, also at Durdlestone Bay. These 

 remains were at first supposed to be reptilian, differing only in 

 species from those of lizards of a somewhat similar size with which 

 they were associated. We are indebted to Prof. Owen, to whom they 

 were submitted, for the important discovery, after a careful removal 

 of the matrix which concealed their most characteristic features, that 

 they belonged to the Mammalian class. 



Guided by that accurate knowledge of osteology and comparative 

 anatomy which he ever brings to bear on subjects of this kind. Prof. 

 Owen was not slow to discover, on proceeding to examine the charac- 

 ters and forms of the teeth, that these interesting remains not only 

 belonged to the Mammalian class, but that they exhibited the general 

 condition of the molar teeth of small insectivorous mammalia. Let 



