334 ANNUAL OF SCIENTIFIC DISCOVERY. 



fact is important, when considered in connection with the recent at- 

 tempts made in Germany to establish the presence of pus in the at- 

 mosphere, and in this manner explain the transmission of certain forms 

 of disease. The existence in the atmosphere of a large number of the 

 spores of cryptogamia, gives a probable explanation of the transmission 

 of certain of the algas and fungi, which infest the bodies of men and 

 animals. 



In dust collected after a winter's snow-storm on plates of glass covered 

 with glycerine, Professor Wyman detected, in addition to particles of 

 mineral dust, probably that of coal ashes and of soot, spores of crypto- 

 gams, starch granules, and pollen. Fragments of coniferous and other 

 woods were also found. The objects most unexpected at this season 

 of the year were the grains of pollen. It was suggested whether these 

 might have been derived from the trees, where they may have been 

 lodged in the crevices of the bark, or other irregularities of the surface, 

 and from time to time detached by the wind. 



