118 HABITS. 



so common a sight. Our Tiger Swallow-tails 

 throng about lilac-blossoms, and become so in- 

 toxicated that on one occasion a friend of mine 

 caught sixty of them at once between his two 

 hands. 



The butterflies I have mentioned show an ap- 

 parent fondness for each other's company, apart 

 from the attractions of the flowers or the muddy 

 road ; indeed, there are very few butterflies which, 

 at the time &f their greatest abundance, do not 

 show a tendency to congregate. The Monarch, or 

 Milk-weed Butterfly (Danais Plexippus) [Fig. 

 106], for example, may be seen quite by himself, 

 sailing majestically over the fields, until late in 

 the season, when, having multiplied to excess, 

 vast swarms are found together ; together they 

 mount in the air to lofty heights, as no other but- 

 terfly appears to do, and play about in ceaseless 

 gyrations ; and sometimes they crowd so thickly 

 upon a tree or bush, as by their color to change its 

 whole appearance [Fig. 107] ; occasionally we 

 hear of the migrations of butterflies in swarms, 

 but they are of rare occurrence, and have mostly 

 been observed in the tropics. Mr. W. Edwards, 

 however, relates* how, from the top of Pegan Hill, 

 in Natick, Massachusetts, he saw such a moving 

 swarm flying steadily for hours in a single direc- 



* American Naturalist, xi., 244. 



