15 
Minnesota eggs, Mr. Thomas had better lack, and reared several to the 
winged condition. We repeatedly dispatched living specimens both of 
the pupa} aud the mature insects from Texas, Kansas, and Iowa to our 
office clerk, Mr. Th. Pergande, St. Louis, but with no more favorable 
results, as he entirely failed to obtain eggs, and the females, wheu dead, 
were found, upon examination, to contain none. This want of fecund- 
ity, though not universal, was quite general with the insects of 1877, 
and is in keeping with the general experience as to the sickly aud de- 
generate nature of the brood. 
It is quite manifest, therefore, that in answering the question we have 
just asked we can do so only in a general aud qualified manner. The 
number of eggs produced by a well-developed locust will range from 100 
to 150, if we consider species generally. We have counted 171 in one 
mass of Oaloptenus differ entialis; from 120 to 130 in those of (Edipoda 
pharuecoptcra, and about 120 in that of Acridium americanum. The great 
probability is that the eggs of such species are all laid at once. In spe- 
cies like spretus, which rarely lay more than 30 eggs in one mass, it were 
natural to infer that different layings take place, even did the facts at 
hand not prove such to be the case. In 1876 the insects were pushing 
continuously southward from the middle of August till the end of October, 
aud during most of this time they were laying eggs. In fact, throughout 
the country invaded, from Minnesota to south Texas, they continued 
laying till frost, and we know from examinations that many of them 
perished before all the ova had been disposed of. Stragglers were even 
noticed in Texas as late as December. 
To sum up the inquiry, we would give it as our belief that the laying 
season normally extends from 6 to 8 weeks; that it may be shortened 
or lengthened by conditions of weather and climate j that fecundity is 
materially affected by the same conditions ; that the average number 
of egg masses formed is three ; and that the average interval between 
the periods of laying by the same female is 2 weeks. 
The Hatching Process. — Carefully examined, the eggshell is found to 
consist of two layers. The outer layer, which is thin, semiopaque, and 
gives the pale, cream-yellow color, is seen by aid of a high magnifying 
power to be densely, minutely, and shallowly pitted ; or, to use still 
more exact language, the whole surface is netted with minute and more 
or less irregular, hexagonal ridges (PI. I, Fig. 4, a, b). It is a mere cov- 
ering of excreted matter, similar in nature to the mucous or sebific fluid 
already described, which binds the eggs together. The inner layer (or 
chorion) is thicker, of a deeper yellow, and perfectly smooth. It is also 
translucent, so that, as the hatching period approaches, the form and 
members of the embryon may be distinctly discerned through it. The 
.outer coveriug is easily ruptured, and is rendered all the more fragile 
by freezing ; but the inner covering is so tough that a very strong pres- 
sure between one's thumb and finger is required to burst it. How, 
then, will the embryon, which fills it so compactly that there is scarcely 
