80 



have taken specimens dead and very much mutilated, and others alive. 6. Sarrothri- 

 pus ilicanus. Specimens of this moth I have taken on the sharp prickles of the leaves 

 of the holly, Ilex Aquifolium." 



Mr. Spence read the following extract from a newspaper, called ' The Scientific 

 American,' dated March 22, 1851, " On the American Locust (Cicada seplemdecim)," 

 communicated by Dr. Gideon B. Smith. 



" I have made this remarkable insect a special object of study for seventeen years, 

 beginning in April, 1834. During the spring and summer of that year, I made a 

 careful examination of its anatomy and habits, from the perfect larva state to the de- 

 scent of its progeny in July and August into the earth. I have frequently found the 

 larvae since 1834, in the ground, where they went down in that year, from one and a 

 half to two feet from the surface, in oblong cells, varying from an inch to two or three 

 inches in diameter, and generally horizontal. These cells, however, appear to be 

 moveable, that is, the insect digs the earth from one end and packs it in the other. 

 The object of these movements seems to be to obtain fresh vegetable matter on which 

 to feed. The insect obtains its food from the small vegetable radicles that everywhere 

 pervade the earth. It takes its food from the surface of these roots, the moist exuda- 

 tion (like animal perspiration), for which purpose its rostrum or snout is provided with 

 three delicate capillaries or hairs, which it projects from the tube of the snout, and 

 sweeps them over the surface, gathering up the minute drops of moisture. This is its 

 only food : the mode of taking it can be seen by a good glass. 



" It does not puncture the bark, because it has no instrument for such a purpose, 

 and therefore that they puncture the roots of pear-trees and thus kill the trees is erro- 

 neous. It is also an error to say, should a tree on which these larvae have been feed- 

 ing be cut clown, the insects perish for want of food. If a place be found where trees 

 grew in 1834, which were cut down, the land cleared, and even houses built upon it 

 sixteen years ago, the locusts will be there now, and will be seen to emerge from the 

 ground about the 25th of next May. 



" The tract of country that will be occupied this year by the locusts extends from 

 the Patapsco river in Maryland, to Buck's county in Pennsylvania, and from the Dela- 

 ware river to the middle of the range of the Alleghany mountains, including Bedford 

 county, Pennsylvania. 



" There is another locust-district this year in Georgia and South Carolina, a small 

 tract embracing a portion of these States, and another small one in Mississippi. I 

 have the location of thirty from different districts, occupying fourteen of the seventeen 

 years. The other three years are no doubt occupied in the western wilds of N. Ame- 

 rica, between latitudes 43^° N. and 29° S., beyond which parallels I have not been 

 able to hear of them. The locusts will appear about New York in 1860 ; this district 

 extends to the Connecticut river East, and as far North as Washington Co., N. Y., 

 West to Amsterdam in Montgomery Co., and a large portion of New Jersey. 



" In the whole range of Natural History there is nothing more strange than the 

 fact, — which has been established with as much certainty as any fact in Astronomy 

 ever was, — that a little insect, not so large as the smallest ant, should pass into the 

 ground, and remain there seventeen years, and then emerge a comparatively large in- 

 sect ; or that a certain tribe of insects should appear here in immense numbers, ex- 

 actly once in seventeen years, always in the same month, almost on the same day, and 

 same hour. It is indeed wonderful, but it is nevertheless true. 



" The music or song produced by the myriads of these insects, in a warm day, 



