47 
the surface, as indicated at the dotted lines (Fig. 25, e). Butif the 
soil is at all compressed it can make little or no headway, ex- 
cept through the appropriate channel (Fig. 25, d). While 
crowding its way out, the antennez and four front legs are held 
in much the same position as within the egg, the hind legs 
being generally stretched. But the members bend in every 
conceivable way and where several are endeavoring to work 
through any particular passage, the amount of squeezing and 
crowding they will endure is something remarkable. Yet if by 
chance the protecting pellicle is worked off before issuing from 
the ground, the animal looses all power of further forcing its 
way out. Theinstinctive tendency to push upwards is also re- 
markable. In glass tubes, in which I had the eggs hatching in 
order to watch the young, these last would always turn their 
heads and push toward the bottom whenever the tubes were 
turned mouth downwards; while in tin boxes, where the eggs 
were placed at different depths in the ground, the young never 
descended, even when they were unable to ascend on account 
of the compactness of the soil above.” 
‘‘'The above minute account of the manner in which eggs are 
laid, and how the young are enabled to reach the surface, 
plainly indicates one good method by which the hatching of the 
eggs may either be prevented entirely, or by which the young 
may be prevented from reaching the surface. By plowing 
the fields containing eggs of the Rocky-mountain locust, we 
perform two operations: we first of all remove the eggs from 
near the surface and cover them with five or six inches of soil; 
secondly, we invert the position of the hole containing the egg- 
mass, so that instead of its mouth pointing upwards, it now points 
downwards. At all events, the young insects are prevented 
from reaching the surface, it this becomes compact by rain and 
snow. Consequently if we plow during autumn or soon after 
the eggs are laid, we are safe; although if we plow in the spring 
with a normal amount of rain, we also effectually prevent their 
hatching and escape. Plowing has this additional advantage: 
the egg-masses in most cases are thoroughly broken up, the 
individual eggs become surrounded by earth and moisture, and 
being no longer protected by the water-proof coat of dried 
mucous matter, they soon rot and perish.” 
