Scientific Intelligence— Meteorology and Geology. 183 



earth's atmosphere, implying, as all chemists are aware, a corre- 

 sponding augmentation of oxygen, is a^fact of great interest to 

 geology, as shewing that very modification in the constitution of the 

 air which would adapt it to the development of animals progressively 

 higher in the scale of organization, which are known to require 

 a more rapid oxygenation of their blood. — American Journal of 

 Science and Arts, vol. xlvii., No. 1, July 1844, p. 105. 



6. Ehrcnbcrg's Researches on the Distribution of Microscopic 

 Life. — A comparison of the microscopic organisms of Europe 

 with those of other countries, ^vhich Ehrenberg commenced some 

 years ago, has now been extended to Asia, Africa, and Australia. 

 Aided by his method of examining the portions of soil adhering to 

 the roots of plants in herbaria, and by contributions from travellers, 

 of algae and earths containing infusoria, he has been enabled to 

 give a comprehensive view of the minute living forms of an im- 

 mense portion of the surface of the earth. 



In his memoir on the Asiatic forms, the author accompanied his 

 remarks, upon the importance of the most careful observation of the 

 minutest organic forms, by the statement, " that the globular con- 

 cretions of the oolitic limestone of the Jura formation in Germany, 

 as v.ell as in England, appears to be chiefly composed of the shells 

 of Meloniffi." 



He alluded to the different views which have been entertained 

 with regard to the origin of the round granular concretions of ooli- 

 tic limestone, and stated that the idea, that, like peastone, it origi- 

 nated in an incrustation of various small fragments in a former sea, 

 having a high temperature, was improbable and untenable ; for 

 among the round granular conci-etions with concentric coatings, like 

 the peelings of an onion, which might be supposed to have had such 

 an origin, there also often occurred calcareous or siliceous bodies of 

 the same size, which shewed no trace of incrustation ; as, for ex- 

 ample, spines of Echina^, encrinital plates, fragments of shells and 

 minute Polythalamia. All these forms which had existed and 

 remained in the same conditions, but which had received no shelly 

 coverings, prove that the shells of many oolitic concretions cannot 

 be incrustations. Besides, the oolitic concretions have generally a 

 very similar limit with regard to size, while, in the formation of 

 peastone, there is no limit. 



The author stated that he possessed a piece of oolitic limestone 

 from Baden, the concretions of which shewed, in addition to the 

 shells, longitudinal strite — and chambers were visible in the cross 

 section ; so that the structure opposed the supposition of a mere 

 calcareous deposition. The same structure was seen in the Me- 

 lonise from the mountain limestone of Lake Onega in Russia ; and, 

 by means of sections, distinct views of the structure of the MelonifS 

 were also obtained, in a piece of hornstone from the mountain lime- 



