ALG^E. 179 



DapJuiia pulex, seem to speak thus much for the 

 substance, that its original locality was not the atmo- 

 sphere nor America, but most probably either East 

 Prussia or Courland." ^ 



The light thus thrown upon the " Meteor paper 

 which fell from the sky " proves it to have been thin 

 sheets of a compacted Cladophora, or fresh-water 

 alera, intermixed with the siliceous valves of several 

 species of diatoms (called Infusoria by Ehrenberg) 

 and some other minute objects. 



Another similar substance is often found, in these 

 latter days, to which the name of " vegetable flannel " 

 or " natural flannel " is applied. This is found cast 

 up on meadows where streams have overflowed and 

 deposited masses of confervse upon the grass and 

 rushes. This substance is felted in sheets not unlike 

 flannel in appearance, and bleached to a yellowish 

 white by exposure to the sun and air. When it is 

 examined it is found to consist chiefly of interwoven 

 filaments of some species of Cladophora, with which 

 are often mixed the frustules of minute species of 

 Diatomaccse. The origin of the two substances 

 appears to be the same, as also their composition ; 

 but this last has not assumed such a compact papery 

 texture as the former, and, being thicker and heavier, 

 is not so liable to being blown away to a distance, 

 to the dismay of the peaceable inhabitants. 



Dr. Hooker collected in Sikkim, in the dry bed of 

 a stream, a curious white substance, like thick felt 



' " On a Meteoric Pai^er which fell from the Sky, etc.," by Professor 

 Ehrenberg, of Berlin, in Annals of Natural History (1839), vol. iii. 

 p. 185. 



