Miscellaneous. 137 



of trees, they remain two months or sixty days in the pith of the 

 wood before they are hatched and ready to seek their home in the 

 earth ; and as they invariably ascend in May, soon after which the 

 eggs are deposited, it makes their actual residence in the earth two 

 months short of seventeen years. The perfect insect lives about 

 thirty days, and then perishes. In 1840 the cells were found to be 

 from two and a half to four feet below the surface, and without any 

 tube communicating with the top of the ground. The cells are pro- 

 bably water -proof, as the flood of 1832 covered the surface to the 

 depth of six or eight feet in my garden. In 1846 a large number of 

 these insects emerged from the earth under an apple-tree, in the 

 branches of which the parent Cicada had deposited her eggs in 1829. 

 If the water at that time, when only in their third year, had had 

 access to their cells, they must have perished, for it remained over 

 them five or six days. In their cells no appearance of excremen- 

 titious matter was noticed. When their period of entombment is 

 completed, in the seventeenth year, or perhaps earlier, they com- 

 mence working out a smooth cylindrical tube towards the surface, 

 taking care not to approach within reach of frosts, and where examined 

 for the purpose, the tubes have been found to be usually about four feet 

 in length. For constructing their cells and excavating these tubes, 

 their fore-feet are admirably adapted, being much larger and stronger 

 than those for locomotion, and formed with stout claws like the craw- 

 fish. Each pupa is armed with a stout proboscis, one-fourth of an 

 inch long, which usually lies between the fore-legs on a line with 

 the body. A remarkable example of instinct was observed in some 

 which came to the surface under a pile of boards, raised by timbers 

 five or six inches above the earth. The ground was wet, and to en- 

 able themselves to reach the dry boards they continued their cylin- 

 ders up to them, forming thus towers of damp clay in the centre of 

 which they were concealed. These towers were five or six inches 

 high and about an inch in diameter ; they were constructed of lumps 

 of wet earth compacted together in a firm but rough manner. A 

 large number of these towers was found when the boards were re- 

 moved ; some had the top closed, and from these the Cicada had not 

 departed. When they had reached the boards, they crawled along on 

 the under side and came to the open air, where, fixing on a spot 

 favourable to their purpose, they remained attached, until a rupture 

 was made in the cuticle on the back of the thorax, and the perfect 

 insects then with great effort extricated themselves from the armour 

 that had so long protected them in the earth. As there was no 

 further use for the stout claws of the fore-legs after they became 

 denizens of the air, these legs were replaced by two that were small 

 and delicate like the other four. In a few days after leaving the 

 earth they had chosen their mates, and the female soon commenced 

 depositing her eggs in the undersides of the tender branches of trees, 

 by means of an ovipositor resembling an awl or punch, and con- 

 tinued at this for several days. The preceding year's growth of 

 the branches of apple-trees is a favourite wood with them ; — but in 

 Ann. $ Mag. N. Hist. Vol. xx. 10 



