NYMPHALIDM. 153 



actual thousands at Bournemouth. In that year the multi- 

 tudes which appeared all over the Continent of Europe were 

 the theme of the newspapers. Some of the more important 

 notices thereof were collected by Mr. McLachlau, and trans- 

 lated for the Entonwlogidfi' Monthly Magazine. It appears 

 that this migi'atory swarm was first observed in North Africa 

 in the middle of April, appeared in countless numbers at 

 Valencia and Barcelona on April 26th to 30th, and in the 

 Island of Minorca on May 1st to 3rd ; at Sevres, near Paris, 

 on June 15th, great swarms appeared all day long, flying 

 from S.S.E. towards N.N.W. At Strasburg, from June 3rd 

 to 9th, a similar occurrence had been noticed, the insects 

 flying in innumerable quantities towards the north, and con- 

 tinuing even in rainy weather. At Angers, on June 10th, it 

 was estimated that the number passing along a single street 

 in one hour was from 40,000 to 50,000. At Geneva the 

 swarm was said to have obscured the sun for several minutes. 

 At Steyer, in Upper Austria, on June 11th, surprising numbers 

 flew ceaselessly from S.W. to N.E., at between one and two 

 o'clock P.M. 90 to 1 00 per minute were counted in a breadth 

 of about 100 paces, and the swarm was estimated at above, 

 rather than below, 1,000,000. Notices of similar swarms 

 appeared at the same time from many provinces of Italy, 

 and other parts of the Continent. I have extracted these 

 data in order to show the extreme probability, almost 

 amounting to certainty, that the sudden appearance of 

 multitudes in this country was a direct result of the great 

 migratory movement noticed in so many parts of Europe. 

 These August butterflies, the progeny of the June swarms, 

 coming from a warmer climate, had no intention of hyber- 

 nating, but paired and laid their eggs, and in September 

 and October of that year larvfe were commonly to be 

 found on the root leaves of the young thistles which would 

 not grow up for blossoming until the succeeding year. 

 Some of these larvae were collected and reared indoors 

 emerging in November and December, but out of doors 

 all must have been destroyed, by damp or frost, in either 



