THE VEGETABLE KINGDOM. 000 



rise, the little parachute, borne away on the powerful 

 wind, mingles with the stormy clouds, traverses oceans, 

 and then effects a descent upon some distant shore. We 

 are told that after certain hurricanes it is not unusual to 

 see the soil of Spain covered with different aerial seeds 

 brouoht from America. It is to the action of the winds that 

 Linnaeus ascribes the importation into Europe of the Conyza 

 coeridea of Canada, which uoav infests the north of France. 



The air does still more ; in its whirlwinds it carries away 

 entire j^lants and bears them to a long distance, to let 

 them fall there like an abundant living shower. 



Certain lichens from the moimtains of Asia, travelling 

 thus amid the clouds, suck up watery vapours from them 



272. Edible Air-borne Lichen — Lecanora cucalenta. 



and groAV during their accidental peregrination. Tom 

 away from the soil Avhen they are scarcely so large as the 

 head of a pin, they have reached the size of a small nut 

 by the time when, their aerial journey over, they fall far 

 from their native rocks upon the ground below them. 

 This happens with many edible species, which after a 

 storm are seen scattered over the sand of the deserts. 



These plants, which seem thus to fall from the sky, 

 sometimes form thick layers on the soil and yield the 

 exhausted traveller an agreeable food. The providential 

 manna, on which the Hebrews fed while wandering in the 

 desert, doubtless arose from showers of edible lichens, for 

 it is these plants which seem always to produce them. 



