120 MICROSCOPICAL OBJECTS FOUND 



llotalia globulosa, R.turgida, Textillaria aciculata, 

 and T. globulosa, the characteristic Foraminifera 

 of the Chalk of England, having all been found 

 living in the North Sea, at Cuxhaven. This alone 

 is sufficient to show the impropriety of trusting 

 to them as a means of identifying the age and 

 geological position of any deposit. 



The same line of argument applies equally to 

 another of M. Ehrenberg's views. He says, — 

 " The idea that the temperature and constitution 

 of the atmosphere and ocean were essentially 

 different at the period of the Chalk formation, 

 and adverse to the organized beings at present 

 existing, naturally acquired more probability and 

 weight, the more decidedly different all the 

 creatures of that period are from those of the 

 present time ; but loses more and more in 

 importance, the less Chalk proves to be a 

 chemical precipitate, and the more numerous 

 the forms, agreeing with those of the present 

 day, become by renewed enquiry. Nay, there 

 is not the least doubt that the perfectly ascer- 

 tained identity of a single species of the present 

 day, with one of those of the Chalk, renders 

 doubtful the necessary transformation of all the 

 others, subsequently to the formation of the 



