LIFE HISTORY 
19 
F., in twelve hours, but at 45 ° F. they did not hatch 
until the third day, and then only when placed in a 
warmer temperature for the purpose of studying them 
under the microscope. 
Doctor Hewitt has carefully observed the hatching 
of the eggs, and this is a process which has now be¬ 
come familiar to many Americans through the excel¬ 
lent moving-picture exhibitions given under the auspices 
of the American Civic Association from films prepared 
in England at the expense of Mr. Daniel Hatch, Jr., 
Chairman of the Fly-fighting Committee of the Asso¬ 
ciation. Doctor Hewitt’s description follows: 
“A minute split appeared at the anterior end of the 
dorsal side to the outside of one of the ribs [refer¬ 
ring to two distinct curved rib-like thickenings along 
the dorsal side of the egg] ; this split was continued 
posteriorly and the larva crawled out, the walls of the 
chorion [the eggshell] collapsing after its emergence. 
The Larva 
We have just described how the egg hatches. The 
young larva as it issues from the egg is a slender 
