1298 Rocer C. SuirH 
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The embryo pushes the burster through the chorion to its entire 
length, and may by upward shifts widen the rent. Then its head 
is forced through the rent, causing the chorion to tear above. The 
head of the embryo bursts through the embryonic molt at this time or 
earlier, so that the molt, with the burster, is left behind. The molt is 
attached to the inside of the chorion in the midventral line. The mouth 
parts and the legs retard emergence so that the larva forms a loop over 
the egg. The mouth parts are slowly withdrawn from the molt, and 
then the larva emerges fully with the exception of the end of the 
abdomen. The larva then rests supported by the tip of the abdomen 
until the chitin hardens, and in a half hour from the beginning of 
hatching it is ready to descend from the shell. (Smith, 1922.) 
The egg burster in Chrysopa oculata 
The egg burster may be readily studied by picking out the embryonic 
molt from the lower part of the opening in the egg shell and mounting 
it in glycerin jelly or balsam. The burster is a thickening and special- 
ization of the chitinous embryonic molt over the anterior mid-dorsal 
region of the head of the embryo. The burster proper 
is almost transparent and is 0.118 millimeter long and 
0.029 millimeter wide at the lobe. In cross section it 
would appear V-shaped with the apex outward. Along 
the front border is a row of very small teeth which 
suggest a saw. The number of teeth varies from 
twenty to thirty and they are irregularly spaced. On 
the upper part is a prominent projection, referred to 
as a lobe. This lobe may or may not have a short, 
Fic. 156 EGG BURST- sharp tooth at its apex, but it bears teeth on the under 
Se aides Bates side. The bursters of the species studied are all of 
ERAL VIEW this type. 
THE LARVA 
General characteristics 
The larva at hatching is about 2 millimeters long, is sparsely beset 
with long setae, and is predominately gray in color. The average 
measurements of five newly hatched larvae of Chrysopa oculata were as 
follows: 
Total lensth of Mlarval 2 1.88 millimeters 
queneth sob. heads). ee eee ee 0.54 millimeter 
Tenethsotmmandibless eee eee 0.34 milhmeter 
Widthrof shead: 5 ce ee ae es eee 0.33 millimeter 
Width of body at metathorax...................... 0.38 millimeter 
Length of longest setae on body...............- 0.47 millimeter 
