398 Concluding Remarks. 



are deposited there without having experienced the slightest 

 wearing previous to their becoming fossil; 3rd and lastly, 

 that it extended to the whole of the white chalk of England. 



Concludincr Remarks. 



The preceding extracts from the labours of Dr. Ehrenberg 

 and M. A, d'Orbigny show that microscopic Polythalamia 

 are found in all calcareous formations from the lias upward; 

 but in England they have been lately discovered in still deeper 

 strata. Mr. Tennant was, I understand, the first to announce 

 their discovery in 1839 in the mountain limestone of England. 

 In 1840 they were also met with in the Kendal limestone, 

 from which Mr. Lonsdale has prepared thin slices mounted 

 on glass, which appear transparent under a strong light, ex- 

 hibiting the crowded state of the microscopic Polythalamia in 

 great perfection. Mr. Bowerbank also has been led to turn 

 his attention to this subject by examining the siliceous bodies 

 of the chalk, green sand, and oolites*. 



I had written thus far, when an interesting article by the 

 Rev. Dr. Buckland, in reference to the researches of Dr. Ehren- 

 berg up to 1839, met my eye, entitled, "On the agency of 

 Animalcules in the formation of Limestonef," which notices 

 in particular the researches of MM. Tennant and Darker on 

 this subject in the Derbyshire limestone and the Stonesfield 

 slate, as well as the labours of Mr. Bowerbank, referred to 

 above, and conveying judicious reflections. Dr. Buckland 

 justly remarks, that in the application of the microscope 

 from the living to the fossil Infusoria and Foraminifers we are 

 commencing a new and important era in Palaeontology. A 

 very interesting branch of the inquiry will be to ascertain 

 whether these microscopic bodies retain throughout a distinct- 

 ive character in the several formations into whose composition 

 they enter. In the unbounded field of nature presented to 

 the consideration of the Microscopical Society of London 

 lately established, no subject appears more worthy of their 

 attention than an examination of the microscopic organic con- 

 stituents of all the older limestone formations of the British 

 Isles, as well as of other countries; and it is much to be de- 

 sired that this attention may not be wanting, although the 

 concurrence of many labourers may be required to reap a 

 harvest of great promise, yet of indefinite extent. 



* Proceedings of the Geological Society, March 11, 1840. 



f Edinburgh New Philosophical Journal, January to April, 1841. 



