EXTERMINATION IN ANIMAL LIFE. 283 



has taken place in the past. The views of the earlier naturalists 

 on this subject have shared the fate of many species, and become 

 practically extinct. Even Linnaeus evidently believed in the 

 permanence of types. He wrote : " Thus, whilst all things are 

 purified, all things are renewed, and an equilibrium is main- 

 tained ; so that of all the species originally formed by the Deity, 

 not one is destroyed."* 



When we begin to analyse the causes that have operated in 

 the destruction of so much animal life, two main factors are at 

 once recognized — (1) natural phenomena, in which the action of 

 man is entirely absent or scarcely perceptible ; (2) the sole 

 agency of man, either directly or indirectly. The first must 

 have been the most gigantic, acting long before the appearance 

 of man upon the earth, unremembered, unrecorded, due to 

 events in which our own lives played no part ; not necessarily 

 more cataclystic than what occurs now, but covering an infinity of 

 time compared to our own little era, and forming a resultant which 

 we still imperfectly appreciate. The very walls of our museums, 

 the outside structures that protect and shield the examples 

 of a too often vanished fauna and flora, are frequently com- 

 posed of or contain the relics of long extinct species. The Leitha 

 limestone, largely used for building purposes in Vienna, comes 

 from extensive nullipore banks in the Leitha Mountains, south- 

 west of Vienna on the Hungarian frontier ; and just as in Paris 

 many of the finest buildings are constructed of the consolidated 

 calcareous remains of Foraminiferae, so in Vienna are the in- 

 crustations of certain red seaweeds put to this purpose.! Some 

 of the Egyptian pyramids are composed of limestone nearly 

 solely consisting of the remains of extinct Nummulitids, and the 

 cathedral of Gerona is built of the same material. Beneath 

 London itself, in the clay on which it stands, are the embedded 

 remains of a long extinct plant and animal life. Many of the 

 fruits, for instance, are the produce of palm-like trees (Nipa) 

 akin to the screw pines, and similar to those now growing in 

 Bengal, in the Philippine Islands, and elsewhere in the East 

 Indian Archipelago ; while others are the cones of plants {Pro- 



* Preface to ' Museum Eegis Adolphi Friderici.' Transl. by J. E. Smith, 

 "Tracts relating to Nat. Hist.," p. 18 (1798). 



f Gf. Kerner & Oliver, ' Nat. Hist. Plants,' vol. ii. p. 667. 



z 2 



