HABITS AND CHARACTERI8TII 8. 11 
its aerial existence by the attacks of birds and other vertebrate ene- 
mies, which fatten on it in enormous numbers. For this specie- this Lb 
a most important consideration, for it is naturally sluggish and help- 
less and seems to lack almost completely the instinct of fear common 
to most other insects, which leaves it an easy prey to insectivorous 
animals. The almost entire absence of fear and consequent effort to 
save itself from danger by flight or concealment is apparently a con- 
sequence of the long intervals between its aerial appearances. 
The greatest check on the species has been in the advent of Euro- 
peans on this continent and the accompanying clearing of woodlands 
and increase of settlement. The vast areas in the more densely popu- 
lated East, which were once thickly inhabited by one or the other of 
the broods of the periodical Cicada, are rapidly losing this character- 
istic, and the Cicada will doubtless appear in fewer and fewer numbers 
in all settled districts. A recent important factor which is assisting 
in this particular is the English sparrow, and it has been shown by 
Professor Riley and later observers that in and about cities nearly all 
of the few Cicadas which still emerge under these more or less unfa- 
vorable conditions are devoured by this voracious bird. 
The rapid disappearance of the Cicada as a result of the clearing of 
forest areas, and the conditions which accompany settlement, is notably 
shown in the case of Brood I which covers in the main a compact terri- 
tory in the valley of the Connecticut River in the State> of Massachu- 
setts and Connecticut. 
In a recent letter to the writer. Mr. George Dimmock. who has made 
a special study of this brood in the northern part of the town of Suf- 
field. Conn., says: ^-Wlien I saw them in I860 the Cicadas were so 
abundant that small bushes and undergrowth in the rather sparse 
woods in which they occurred were weighted down with them." In 
1886 he was unable to visit the region, but was 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 going 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 reduc- 
tion was so rapid that he doubted if any of them would appear in 190 3 .'" 
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 white settlement. It is inter 
esting. therefore, in thought to trace the history of this species bark- 
ward, taking as time measures its periodic recurrences, until in 
retrospect it is possible to fancy its shrill notes jarring on the ears of 
