22 THE PERIODICAL CICADA. 
is more than probable that in many places a few and scattered speci- 
mens will appear in off years which can not be recorded as precursors 
or belated specimens to any of the established broods, and which can 
not properly be called a 'brood.' " (1. c, p. 300.) 
Mr. W. T. Davis records 1 the occurrence of scattering individuals on 
Staten Island in both 1890 and 1892, neither of which is a Cicada year. 
These may have been of accelerated or retarded individuals, but possi- 
bly represent either remnants of broods or insignificant broods not 
hitherto recorded. 
It may be mentioned also in this connection that all of the swarms 
or local colonies assigned to any particular brood, either of the 17-year 
or the 13-year race, need not necessarily have had a common origin, and 
quite as probably came into existence independently of each other or 
as offshoots of distinct broods. This is especially liable to be true of 
broods comprising widely separated swarms, or colonies, as does for 
example Brood XVII of this year. 
The largest brood of the 17-year race is Brood XXII, which appeared 
last in 1885 and has been well recorded over a wide extent of country 
since 1715. The largest 13-year brood is No. XVIII, and made its last 
appearance in 1891. It has also a long chronological history and is 
well recorded. These two broods occurred in conjunction in 1868, 
which thus became the great Cicada year of the century. 
THE BROODS APPEARING IN 1898. 
The early summer of 1898 will witness the recurrence of two broods 
of the periodical Cicada, viz, 13-year Brood VII, which is the second 
largest of the 13-year broods, and 17-year Brood XVII, a scattering 
brood occurring in comparatively small colonies over a wide extent of 
territory, and therefore not of great importance. 
Brood VII made its last appearance in 1885. It extends over a broad 
belt of the country, chiefly bordering the Mississippi Biver, but also 
occurring in isolated areas in adjoining States. The main belt reaches 
from southwestern Illinois and western Kentucky southward, covering 
a large portion of western Tennessee and much of northern and cen- 
tral Mississippi. There are numerous outlying colonies extending over 
northern Louisiana up through Arkansas and Missouri and two isolated 
colonies in Georgia. Special interest attends the recurrence of this 
brood the present year on account of the experiments, referred to in a 
preceding section and in Appendix A, concerning the transfer of eggs 
made in its last appearance in 1885, giving it supposedly and artificially 
increased range. 
Brood XVII of the 17-year, or Northern, race is represented by com- 
paratively small colonies in New Jersey, New York, Pennsylvania, 
North Carolina, Virginia, West Virginia ( ?), Ohio, Illinois, Michigan, 
1 Proc. Nat. Sc. Ass'n of Staten Island, Vol. IV, p. 15, February 10, 1894. 
