THE MICROSCOPE IN GEOLOGY. 11$ 



quantity sufficient to produce masses rivalling in bulk 

 and solidity those of the stony corals ot later epochs, 

 and thus to turnish (as there seems good reason to 

 believe) the materials of those calcareous strata, ot 

 whose occurrence in the Laurentian series it had pre- 

 viously been impossible to give a satisfactory account."* 

 Wonderful, truly, it is to reflect that such enormous 

 results are brought about by the operations of an 

 animal of such extreme simplicity. These rhizopods 

 seem to have performed in the seas ot the Laurentian 

 epoch the same part in the production of limestone 

 rocks which was subsequently taken by coral polypes, 

 echinoderms, and mollusks, as well as by minuter 

 forms of Foraminifera ; " and it is a fact not without 

 an important significance/' Dr. Carpenter also remarks, 

 " that this the lowest type of animal life known to the 

 physiologist, should have thus culminated in the very 

 earliest period in the history of the life of our gldfoe 

 with which the palaeontologist is at present acquainted. 

 . , . . . The physiologist has here a case in which 

 those vital operations which he is accustomed to see 

 carried on by an elaborate apparatus, are performed 

 without any special instruments whatever a little 

 particle of apparently homogeneous jelly, changing 

 itself into a greater variety of forms than the fabled 

 Proteus, laying hold of its food without members, 

 swallowing it without a mouth, digesting it ^ without a 

 stomach, appropriating its nutritious material without 

 absorbent vessels or a circulating system, moving its 

 parts without muscles, feeling (if it has any power to 

 do so) without nerves, propagating itself without a 

 genital apparatus, and forming a shelly covering that 

 possesses a symmetry and complexity not surpassed by 

 those of any testaceous animals. "t 



* Dr. Carpenter in Intellectual Observer, vii. 278. 

 ^ Introduction to the Study of the Foraminifera. Ray Society, 

 p. vii. 



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