Miscellaneous. 141 



for the benefit of the warmth and the air, and occasionally peeping 

 forth apparently to reconnoitre, but descending again on the occur- 

 rence of cold or wet weather. 



During their temporary residence in these burrows near the surface, 

 the Cicada grubs, or more properly pupae, (for such they are to be 

 considered at this period, though they still retain something of a 

 grub-like form,) acquire strength for further efforts by exposure to 

 the light and air, and seem then to wait for only a favourable mo- 

 ment to issue from their subterranean retreats. When at length this 

 arrives, they issue from the ground in great numbers in the night, 

 and crawl up the trunks of trees, or upon any other object in their 

 vicinity to which they can fasten themselves securely by their claws. 

 After having rested awhile they prepare to cast off their skins, which 

 in the meantime have become dry and of an amber colour. By re- 

 peated exertions a longitudinal rent is made in the skin of the back, 

 and through this the included Cicada pushes its head and body, and 

 withdraws its wings and limbs from their separate cases, and, crawl- 

 ing to a little distance, it leaves its empty pupa-skin, apparently 

 entire, still fastened to the tree. At first the wing-covers and wings 

 are very small and opake, but, being perfectly soft and flexible, they 

 soon stretch out to their full dimensions, and in the course of a few 

 hours the superfluous moisture of the body evaporates, and the in- 

 sect becomes strong enough to fly. 



During several successive nights the pupae continue to issue from 

 the earth ; above fifteen hundred have been found to arise beneath a 

 single apple-tree, and in some places the whole surface of the soil, 

 by their successive operations, has appeared as full of holes as a 

 honeycomb. In Alabama the species under consideration leaves the 

 ground in February and March, in Maryland and Pennsylvania in 

 May, but in Massachusetts it does not come forth till near the mid- 

 dle of June. Within about a fortnight after their final transforma- 

 tion they begin to lay their eggs, and in the space of six weeks the 

 whole generation becomes extinct. 



Fortunately these insects are appointed to return only at periods 

 so distant that vegetation often has time to recover from the injury 

 they inflict ; were they to appear at shorter intervals, our forest and 

 fruit trees would soon be entirely destroyed by their ravages. They 

 are moreover subject to many accidents, and have many enemies, 

 which contribute to diminish their numbers. Their eggs are eaten 

 by birds ; the young, when they first issue from the shell, are preyed 

 upon by ants, which mount the trees to feed upon them, or destroy 

 them when they are about to enter the ground. Blackbirds eat 

 them when turned up by the plough in fields. Hogs are also ex- 

 cessively fond of them, and, when suffered to go at large in the 

 woods, root them up, and devour immense numbers just before the 

 arrival of the period of their final transformation, when they are 

 lodged immediately under the surface of the soil. It is stated that 

 many perish in the egg state, by the rapid growth of the bark and 

 wood, which closes the perforations and buries the eggs before they 

 have hatched ; and many, without doubt, are killed by their perilous 

 descent from the trees. 



