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Annals Entomological Society of America [Vol. XV, 



was found to be the egg burster. It could be seen that it was 

 bilobed, but the upper lobe showed the more distinctly. In 

 this case the eggs hatched when these characters showed most 

 plainly. The warmth of an electric light bulb after a cool 

 night started the whole mass hatching. 



The first evidence of the beginning of hatching observed 

 with a binocular was a very slight raising and lowering of the 

 mandibles, effected, it is believed, by the embryo working itself 

 upward then receding slightly. The upward movement was 

 somewhat quicker than the downward one. The head was 

 gradually advanced, thereby bringing the burster next to the 

 chorion. This movement continued from one to four minutes 



Fig. 1. The egg burster of Chaiiliodes pectinicornis Linn. X 215. 

 Fig. 2. The egg burster of Chrysopa oculata Say. X 300. 

 Fig. 3. The egg burster of Micromiis posticus Walker. X 300. 



in different eggs observed. Finally the upper lobe punctured 

 the chorion and a slit was cut for the entire length of the 

 burster. The embryo forced the soft clypeal region through 

 the opening, which caused the rent to broaden, then tear, 

 almost entirely at the upper end. The clypeus was trans- 

 lucent to grayish in color, so contrasted sharply with the 

 chorion. The embryo forced its head through the rent, fol- 

 lowed by the thorax, but the chief advance was made by the 

 dorsum. When the embryo had emerged to about half its 

 length, it stopped and prepared to cast the embryonic molt. 



