8i]phone(Bi\ vaucheria. 347 



found along with them in ditches and little waterfalls, and 

 on damp ground. Common as Vaucherm are, they are very 

 remarkable plants, and the investigation of them afforded 

 great delight to the intelligent mind of Yaucher. Their 

 power of resisting cold, and of sustaining high degrees of 

 temperature, is very extraordinary. M. Vaucher mentions, 

 that when he was making his experiments at Geneva, an 

 intense frost set in, and froze the water in a vase in which 

 his Vaucherice were kept. The frost continuing for a 

 fortnight, he feared that, as they were enveloped in ice all 

 that time, they would be completely destroyed; but when 

 thaw came, he found, to his great delight, that they had 

 sustained no injury; and he had the satisfaction of seeing 

 the gi'ains germinating, as if they had never known frost. 

 Were not this power granted to them, and especially to the 

 seeds, they would soon be exterminated, as every winter 

 they are frozen for weeks together. Their power of with- 

 standing great heat is scarcely less remarkable, and not less 

 necessary for the continuance of their existence. A very 

 compact capsule envelopes the spore, and preserves tlie 

 internal moisture from being dried up. Their seed in 

 general ripens before the drought of summer, and when the 

 shallow pools are dried up, the seed lies in the mud, till it 



