148 BERTHA'S VISIT TO HER 



immense flight of butterflies crossing the garden. 

 He immediately went out, and found that they 

 belonged to the species called, in French, La 

 belle Dame ; they were all going in the same 

 direction, exactly from South to North, turning 

 neither to the right nor left ; people moving 

 about the garden did not frighten them ; nor 

 were they even tempted by the numerous flowers 

 there to alight. Their flight was low and steady, 

 but extremely swift; and it continued in a column 

 of several feet broad for more than two hours. 

 As Mr. M. afterwards learned that these butter- 

 flies had been remarkably abundant near Turin, 

 in April and May, he supposes that they had 

 emigrated from Italy ; but, he says, naturalists 

 have been greatly puzzled to account for their 

 having done so in a body, because they do not 

 belong to those species that live in societies. 



He mentioned another singular circumstance : 

 when he \vas on Mount Etna, he saw, to his 

 great astonishment, an immense number of in- 

 sects hovering over the dry lava of one of the old 

 craters ; there was no appearance of vegetation, 

 or of any thing that could supply them with 

 food ; but there they were in a thick mass, 

 flitting about in the sulphurous vapour, which 

 still rose from the crevices. The insect was a 

 species of bug, or cimex. 



Frederick took me this evening to a sunny 

 sand-bank, to shew me a great novelty, which 



