ANxSIVERSARY ADDRESS OF THE PRESIDENT. 217 



enabled him to fulfil in any degree the above-mentioned design, 

 were begun by the desire, and have been carried on chiefly by the 

 liberal aid of that body. 



The concluding part contains a very interesting and instructive 

 introduction, which will enable the reader to follow with far greater 

 pleasure, and more fully to appreciate the value of the special de- 

 tails which follow. He begins by pointing out that first trace of the 

 creation of mammalian quadrupeds which was discovered in the 

 Stonesfield slate of the oolitic series, and it was certainly a most for- 

 tunate accident which brought these minute bones within the sight 

 of a geologist. It is a very remarkable circumstance, that all the 

 researches of geologists, multiplied as they have been since that 

 discovery was made, have not yet brought to light another fragment 

 of the same order of animals, throughout the vast series of deposits, 

 the immense duration of time, that intervened between the Stonesfield 

 slate and the eocene tertiary deposits ; notwithstanding that there 

 are indubitable proofs of the existence during that interval of exten- 

 sive continents, of forests growing on that land, of its being tenanted 

 by other races of animals, and that birds and pterodactyls spread 

 out their wings in the air above it. 



The land that supported the mammalia whose remains are found 

 in the eocene deposits of our island must have been submerged, 

 and must to a great extent have remained so during the miocene 

 period, when the adjoining continent was inhabited by the animals 

 whose remains have been disinterred there from the deposits of the 

 miocene age; for it is in pliocene and post-pliocene deposits that 

 the mammalian remains in the British Islands next present them- 

 selves. There is the most conclusive proof that the animals lived 

 and died, generation after generation, for a long succession of years, 

 in the land where their remains are now found ; evidence which 

 completely " refutes the hypothesis of their having been borne hither 

 by a diluvial current, from regions of the earth where the same ge- 

 nera of quadrupeds are now limited. The very abundance of their 

 fossil remains in our island is incompatible with the notion of their 

 forming its share of one generation of tropical beasts drowned and 

 dispersed by a single catastrophe." 



The author ably discusses the question how the various members 

 of that ancient fauna came into this island. Other and independent 

 geological proofs show that the British Islands were united with the 

 continent when it received its pliocene mammalia, and the zoologist 

 finds the known habits and powers of these mammalia to be in ac- 

 cordance with that configuration of the land. He then considers the 

 no less important question, although it is one more difficult of so- 

 lution — by what processes they became extinct? The subterranean 

 movements which separated our islands from the continent, and sub- 

 merged other parts of these islands, must have produced such changes 

 in the means of subsistence and powers of migration of tht se animals 

 as must have been one great cause of their diminution and eventual 

 extinction ; the loss of a sufficient supply of vegetable food for the 

 greater herbivorous quadrupeds, and, by their diminished numbers, 



