EMBRYOLOGY OF THE MOLE-CRICKET 



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FIG. 505. Embryology of the mole-cricket: 1, egg in which the amoeboid nuclei (abo) are 

 moving toward the surface ; 2, egg in which the nuclei (abc) have reached the surface, and show 

 an active nucleus-formation ; 3, the blastoderm-cells have no nucleus, and are placed at equal distances 

 apart ; 4, the blastoderm-cells now forming a continuous layer ; 5, cross-section of the egg with 

 blastodermic disk, also showing the disposition of the endodermal cells ; 6, cross-section of the 

 blastodermic disk, with the myoblast cells (mb) already formed ; 7, cross-section through the thorax 

 of the embryo, the body-cavity extended into the limbs. 



abc, ainceboid blastodermic cells. 

 be, blastoderm-cells. 

 bl, blastoderm. 



LETTERING. 



en. endodermal cells. 

 M", cavity of the myoblast. 

 tub, myoblast cells. 



N, nerve-furrow. 

 P, primitive groove. 

 pd, primitive disk. 



