14 THE PERIODICAL CICADA, 
informed that very few of the insects appeared that year. In 
explanation of this he writes: ‘‘ The woodland in the vicinity has 
been steadily reduced and the cicadas, of which there are records 
evoing back about a century, seem to be dying out. The owner of the 
land where the cicadas appeared (a man born in 1815, died in 1892) 
informed me that the rate of reduction was so rapid that he doubted 
if any of them would appear in 1903.” 
To the lover of nature there is something regrettable in this slow 
extermination of an insect which presents, as does the periodical 
Cicada, so much that is interesting and anomalous in its habits and 
life history. During the long periods of past time the species has 
recurred with absolute regularity except as influenced by notable 
changes in the natural topographical conditions and the despoliation 
of forests which has followed the path of settlement by the white man. 
It is interesting, therefore, in thought to trace the history of this 
species backward, taking, as time measures, its periodic recurrences, 
until in retrospect it is possible to fancy its shrill notes jarring on the 
ears of the early colonists or listened to in the woodlands bordering 
the ocean by the still earlier discoverers and explorers. Still more 
remotely one can picture its song causing wonderment to the savage 
Indians who attributed to it baleful influences, and yet, less dainty 
than their white followers, used the soft, newly emerged cicadas as 
food; or further back in time, when it had only wild animals as 
auditors. With these long-time measures our brief periods of days, 
weeks, months, and years seem trivial enough. 
THE RACES, BROODS, AND VARIETIES OF THE CICADA. 
Much obscurity must always attach to the past history of this insect 
and the origin of its peculiar habits, and notably the causes and con- 
ditions which have led to the establishment of the long underground 
existence and the equally extraordinary regularity in time of emer- 
gence at the end of this period. Explanations may, however, be sug- 
gested for some of its peculiarities as presented in its life at the present 
time—as, for example, the origin of the two distinct races, one with a 
17-year period and the other with a 13-year period, with both of 
which a small variety occurs, and the existence of a multitude of dis- 
tinct broods occupying the same or different territory and appearing 
in different years but with absolute regularity of periods. 
A SEVENTEEN-YEAR RACE AND A THIRTEEN-YEAR RACE. 
One of the greatest difficulties in solving the problem of the broods 
of this insect and their geographical limits was removed by the dis- 
covery of the existence of two distinct races—namely, one requiring 
seventeen years for its development and limited geographically, in a 
