2r)0 On (he Fossil Auiinah of the Chalk Fonnatioti. 



10. In consequence of the mass-building Infusoria and 

 Polythalamia, the secondary formations can now no longer be 

 distinguished from the tertiary ; and in accordance with what 

 has been above stated, masses of rock might be formed even 

 at the present time in the ocean, and be raised by volcanic 

 power above the surface, the great mass of which would, us 

 to its constituents, perfectly resemble the chalk. Thus, then, 

 the chalk remains still to be distinguished by its organic con- 

 tents as a geological formation, but no longer as a species of 

 rock. 



11. The power so conspicuous in the organic beings under 

 consideration is, according to experience, .so immensely great, 

 even in its influence on the inorganic, that, with the concur- 

 rence of favourable circumstances, they alone might give rise 

 to the greatest changes in the distribution of the solid land of 

 the earth in the shortest space of time, especially in the 

 water ; and the ascertainable extent of such influences, how- 

 ever great, remains constantly small in comparison to thoie 

 that are possible, consequently do not give, by their magni- 

 tude, any certain measure of periods of time. 



12. The correctness of the above expositions is not founded 

 on individual opinion, formed from hasty inspections of trifling 

 objects ; but the microscopic objects on which the opinions are 

 based (though fading from our notice as individuals, yet, by 

 their number, forming mountains and countries), are acces- 

 sible to any comparison in distinct preparations, made accord- 

 ing to the methods already described; and almost all the 

 forms here mentioned, especially all the more important ones, 

 have been carefully preserved by me, and laid before the 

 Academy. 



13. Thus then, there is a chain, which, though in the indivi- 

 dual it be microscopic, yet in the mass a mighty one, connect- 

 ing the organic life of distant ages of the earth, and proving 

 that it is not always the smaller, or most deeply lying, which is 

 the liase and the type of those which are larger and nearer the 

 surface on our earth ; aiid, moreover, that the dawn of organic 

 nature, co-existent uilh us, reaches farther back into the history 

 of the earth than had hitherto appeared. 



