THE PERIODICAL OR SEVENTEEN-YEAR CICADA AND 
ITS THIRTEEN-YEAR RACE. 
The metamorphoses of insects, their instructive industry, their quar- 
rels and their instincts afford abundant food for our love of the marvel. 
ous; but few species can claim such a singular history as can our Peri- 
odical Cicada. We are moved to admiration in contemplating the fact 
that an insect, after living for nearly seventeen years in the bowels of 
the earth, should at last ascend from its earthy retreat, change its 
sluggish, creeping, and wingless form, and, endowed with the power of 
flight, become a denizen of the air and enjoy the full glory of the sun. 
But our wonder increases when we reflect that this same insect bas ap- 
peared in some part or other of the United States at regular intervals 
of seventeen years for centuries, aye, for ages, in the past! Long ere 
Columbus trod American soil this lowly insect must have appeared 
regularly at its appointed time. It must have filled the woods with its 
rattling song, when none but wild beasts and savages were present to 
hear it. To me there is something pleasant in the idea that through 
its periodicity we are enabled with tolerable certainty to go back in 
thought, for centuries in the past, to a particular month of a particular 
year, or even‘to a given day, when the woods resounded with its song 
in the same manner as they did in 1868, or will the present year. 
It was my good fortune to discover that besides the 17-year broods, 
the appearance of one of which was recorded as long ago as 1633, there 
are also 13-year broods;* and that, though both sometimes occur in 
the same States, yet in general terms the 17-year broods may be said 
to belong to the northern and the 13 year broods to the southern 
States, the dividing line being about latitude 38°, though in some places 
the 17-year broods extend below this line, while in Illinois the 13-year 
breods runs up considerably beyond it.t 
* See Journal of Agriculture, Saint Louis, June 13, 1868. 
tFour months after I had published the above discovery I was gratified to find that 
Dr. Gideon B. Smith, of Baltimore, Md., in an unpublished manuscript communicated 
tome by Dr. J.G. Morris, of the same city, had made the same discovery, though he 
had never given it to the world; while five years later I learned through correspond- 
ence with Dr. D. L. Phares, of Woodville, Miss., that he had even anticipated Dr. 
Smith. There is nothing in Dr. Smith’s manuscript to show that he was led to his 
conclusion by Dr. Phares, but the latter has, in Southern Field and Factory (published 
at Jackson, Miss.) for April, 1873, an extended article in which he claims to have 
published the fact of a periodical 13-year brood in the Woodville (Miss.) Republican 
5 
