273 



Eels, Mites, Etc. 



Anguillula jluviatillis. 



Alacrobioties americamis. 



Water Mite, sp. ?. 



Mite, sp. ? ; probably terrestrial. 



Entomontraca, resembling Diopiomu.". 

 KOTIFEEA. 



Rotifer vulgaris, 



Rotifer, 2 sp. ?. 



Philodimi aculeata. 



Rotifer, eggs, sp. ?. 

 Alg^. 



Nostic lichenoides, ?. 



Pratococoeus vindis. 



Spii-ogyra, sp. ?. 



Osciilaria, sp. ?. 



Diatomes, species, ?. 

 Examples of lichens rich in the a([uatic organisms above listed were sent to 

 half a dozen prominent microscopists with the request that they report the things 

 found in them, and whether the finding of such creatures in such habitats was 

 new; and if not they were requested to cite some article or work of reference giv- 

 ing information upon the matt«r. 



All expressed surprise at the find and failed to cite any work of reference, 

 save a distinguished lady of Pennsylvania, who referred to Dr. Joseph Leidy 

 (XII vol. Hayden's Geol. Rep., 1870), where, in speaking of Rhizopods, he says, 

 substantially: "'While essentially aquatic," they occur wherever there is moist- 

 ure, commencing with one's own doorstep and extending to ocean's depth, and 

 even upon the bark of growing trees, etc., etc. 



The theory generally advanced to account for the sudden appearance of 

 countless numbers of Bacteria, Infusoria, Rhizopoda, etc., in cisterns, watering 

 troughs, transient pools and puddles of water, is that they or their eggs or germs 

 have been gathered up from dried-up ponds and ditches by the summer winds 

 and carried for long distances and deposited on walls and roofs, etc., from whence 

 they are washed by copious rains and afterward germinated, or are developed or 

 revived. 



While this may be true in part as to some of the almost structureless Pro- 

 tozoa, it would seem scarcely sufficient to account for the appearance of the more 

 highly organized Rotifers, Anguillula and mites, in the driest of dry lichens, in 

 every stage of development from egsr to the full-grown animal, and that in the 



