INJURIOUS AND BENEFICIAL INSECTS. 539 
and a half feet averaging probably eighteen-inches ; these seemed 
to be the work of one insect on each twig, showing a wonderful 
fecundity. 
“ The recurrence of three ‘ locust-years’ is well remembered in 
this locality—1834, 1857 and 1868. There has been no variation 
from the usual time, establishing the regularity of their periodical 
appearance.” ` 
As regards the time and mode of hatching, Mr. S. S. Rathvon 
of Lancaster, Pa., contributes to the same journal some new and 
valuable facts, which we quote: ‘‘ With reference to the eggs and 
young of the seventeen-year cicada, your correspondent from 
Haverford College, Philadelphia, is not the only one who has failed 
to produce the young by keeping branches containing eggs in their 
studios. I so failed in 1834 and 1851, and indeed I have never 
heard that any one has succeeded in that way, who has kept them 
for any great length of time. In the brood of 1868, the first ci- 
cadas appeared here in a body, on the evening of the second day 
of June. The first pair incoitu, I observed on the 21st, and the 
first female depositing on the 26th of the same month. The first 
young were excluded on the 5th of August. All these dates are 
some ten days later than corresponding observations made by my- 
self and others in former years. On the 15th of July I cut off 
some apple, pear and chestnut twigs containing eggs, and stuck 
the ends into a bottle containing water, and set it in a broad, shal- 
low dish also filled with water, the whole remaining out of doors 
exposed to the weather, whatever it might be. The young con- 
tinued to drop out on the water in the dish for a full week, after 
the date above mentioned. I could breed no cicadas from branches 
that were dead and on which the leaves were withered, nor from 
those that from any cause had fallen to the ground, and this was 
also the case with Mr. Vincent Bernard, of Kennet Square, Ches- 
ter county, Pa. After the precise time was known, fresh branches 
Were obtained, and then the young cicadas were seen coming forth 
in great numbers, by half a dozen observers in this county. As 
the fruitful eggs were at least a third larger than they were when 
| first deposited, I infer that they require the moisture contained in 
living wood to preserve their vitality. When the proper time ar- 
rives and the proper conditions are preserved, they are easily bred, 
and indeed I have seen them evolve on the palm of my hand. The 
yes of the young cicadas are seen through the egg-skin before 
; it is broken.” 
