244 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
ened and contracted, reaches near the mouth. The long antennz pro- 
ject in front of the head and follow the curve of the body and the long 
legs are folded up in the central space. At an earlier embryonic stage 
the abdomen is enormously enlarged and the members are correspond- 
ingly small. The young walking-sticks measure at birth 4.5™, and with 
their feelers and legs outstretched, nearly double that length. They 
are invariably, during early life, of a uniform pale yellowish-green color, 
and as they have a habit in their earlier days of keeping near the 
ground, this, coupled with a great readiness to drop whenever disturbed, 
serves to protect them from observation. They may for these reasons 
occur in great numbers in the early part of the season without being sus- 
pected. The insect changes very little in appearance from birth to ma- 
turity except so far as color is concerned, and molts but twice. Growth 
is rapid, averaging, under favorable circumstances, about six weeks from 
birth to maturity. With age the green color gives way to various shades 
of gray and brown. In this way we find great correspondence with its 
surroundings. While the vegetation is green, the specters are green 
also; when the foliage turns in autumn, they change color correspond- 
ingly, and when the foliage is stripped they so closely resemble, in both 
appearance and color, the twigs upon which they rest—the habit of 
stretching out the front legs and feelers greatly enhancing the resem- 
blance—that when they are few in numbers it is difficult to recognize 
them. A few green specimens, more particularly of the males, may 
always be found, even among the mature individuals. 
In contemplating these singular creatures and their wonderful resem- 
blance to the oak vegetation upon which they occur, one cannot help 
noticing still further resemblances. They are born with the bursting of 
the buds in the spring; they drop their eggs as the trees drop their . 
seeds, and they commence to fall and perish with the leaves, the later 
ones persisting, like the last leaves, till frost cuts them off. 
ITS APPEARANCE EVERY ALTERNATE YEAR. 
As will have been already noticed, Mr. Snow has found from his own 
observations that the insects were injuriously abundant every other 
year, and I have been interested in endeavoring to find an explanation 
of this fact. ‘The increase of the insect’s natural enemies whenever they 
- become excessively abundant, and the consequent decrease of the plant 
feeder the following year, undoubtedly have something to do with it; ‘ 
but there is also good evidence that a great many of the eggs remain 
on the ground for two consecutive winters before hatching. Messrs. 
Tt. W. Bringham and L. Trouvelot have both found from experience 
that the eggs of this insect for the most part hatch only after the inter- 
val of two years,* and an examination made of a large number, which 
I have myself kept the present winter, shows that while some have pro- 
ceeded far in embryonic development, others show no development what- 
ever, thus corroborating the experience of these gentlemen. 
We may very justly conclude, therefore, that the species will only be 
injurious every alternate year. 
NATURAL ENEMIES. 
Among the natural enemies of this Walking-stick, Mr. Snow has ob- 
served that the crows were very abundant about them, as well as some 
* Proc. Bost. Soc. Nat. His., Vol. XI, pp. 88 and 89, 
