86 MICROSCOPICAL OBJECTS FOUND 



of the Chalk, as well as of the existing warmer 

 seas, where Polythalamia abound ; whilst we are 

 going in opposition to analogy in having recourse to 

 some mysterious theory of chemical precipitation, 

 — a process which scarcely finds an illustrative 

 parallel in the unaltered strata of either the Cre- 

 taceous, Tertiary, or recent eras. Observation 

 also confirms the probability of this, by shewing 

 that similar Foraminifera and other minute 

 organisms do exist amongst the older strata, as 

 well as amongst the more recent ones ; these 

 microscopic forms having occasionally escaped 

 the obliterating influences that have caused such 

 an extensive destruction amongst the greater 

 number. 



M. Ehrenberg has already discovered Forami- 

 nifera in the compact flints of the Jura Lime- 

 stone, at Cracow. In one or two instances, I 

 have succeeded in detecting the soft animal, 

 closely resembling fig, 29, calcified and enclosed 

 in a pisolitic granule, from the Yorkshire Coral- 

 line Oolite, and have also found well-marked 

 evidence of their existence amongst the oolitic 

 granules of the Bath Oolite. Dr. Buckland 

 quotes the discovery of microscopic shells in 



