1 82 ROMANCE OF LOW LIFE AMONGST PLANTS. 



showers. The colour is yellowish, or ochreous, from 

 oxide of iron, and not grey like the true African dust, 

 about one-sixth of the mass being organic. None of 

 the species are characteristic African forms, and 

 Synedra cntomon is South American. Hence it is 

 concluded that the showers of the Atlantic, of Malta, 

 and of Genoa are in general alike in organic as well 

 as inorganic constitution, and in the absence of cha- 

 racteristic African forms ; and this resemblance is the 

 more surprising as the observations extend through 

 the long period of sixteen years. They are also 

 alike in the brownish-red colour of the dust. 



The sirocco dust which fell at Lyons, October 17, 

 1846, afforded sixty-seven species, besides minute 

 portions of plants, of which thirty-nine belonged to 

 Diatomacese. In this shower the organic forms make 

 up about one-eighth of the mass. In general cha- 

 racter, including colour, there is a close resemblance 

 to the products of the Atlantic showers, and the 

 others above described. The species are nearly all 

 of fresh-water or land origin, one-seventh only being 

 marine species. There are two South American 

 species, the Eunotia pileus, and Hiviantidium 

 zygodon. 



A storm of so-called red snow in Puster Valley, in 

 the Tyrol, March 31, 1847, owed its colour to a 

 coloured dust, much resembling that of the Atlantic, 

 its tint being brownish red. It afforded, as obtained 

 from two localities, sixty-six organic forms, one-third 

 of which were diatoms. The large majority of the 

 species are known as fresh-water and continental 

 forms, only two species being marine. There is a 



