19 
on light dry soils and on south and southeast exposures; latest on low, 
moist, and shaded or tenacious ground. 
We see, therefore, that the hatching will not alone vary according to 
temperature and the earliness or lateness of the spring, but that it is 
quite variable under the same conditions. In every instance there will 
be a few hatching when the first hatched in the same locality are getting 
wings ; and we give it as a general rule that the bulk of the eggs hatch 
out in the different latitudes about as follows : 
In Texas, from the middle to the last of March. 
In the southern portions of Missouri and Kansas, about the second 
week in April. 
In the northern parts of Missouri and Kansas and the southern sec- 
tions of Iowa and Nebraska, the latter part of April and first of May. 
In Minnesota and Dakota the usual time for hatching ranges from 
early in May in the southern portions to the third week in the northern 
extremity. 
In Montana and Manitoba, from the middle of May to the first of 
June. 
In short, the bulk of the insects hatch in ordinary seasons about the 
middle of March in latitude 35°, and continue to hatch most numerously 
about four days later with each degree of latitude north, until along the 
forty-ninth parallel the same scenes are repeated that occurred in south- 
ern Texas seven or eight weeks before. 
From a number of experiments which we have made on the eggs, we 
conclude that, with a constant temperature of 85° F., with favorable 
conditions of soil, the eggs will hatch in from four to five weeks after 
they are laid, and in a temperature of 75° F. in about six weeks. Dr. 
Riley has had the eggs of Caloptenus atlanis (laid in July) hatched in 
from three to four weeks; those of Tragocephala viridifasciata (laid in 
June) in three weeks ; and those of Acridium americanum (laid in July) 
in rather more than a month. 
Habits of the young or unfledged Locusts in the temporary Region. — The 
habits of the young insects as they occur in the temporary region, and 
particularly in the country south of the forty-fourth parallel and east 
of the one hundredth meridian, are as follows: Although possessed of 
remarkably active powers from the moment they leave the egg^ yet so 
long as x^rovision suffices for them on their hatching-grounds the young 
remain almost stationary and create but little apprehension. As soon, 
however, as the supply of food in these situations is exhausted, they 
commence to migrate, frequently in a body a mile wide, devouring, as 
they advance, all the grass, grain, and garden-truck in their path. The 
migrating propensity is not developed until after the first molt, and often 
not till after the second or third. Up to that time they are content to 
huddle in warm places, and live for the most part on weeds, and espe- 
cially on the common Dog-fennel or May- weed (Maruta), where it is 
present. 
