248 



ROBERT W. HEGNER. 



TABLE V. 



EXPERIMENTS IN KILLING PARTS OF YOUNG EMBRYOS. 

 Leptinotarsa decemlineata Series L.D. 016. 



end of the tail fold (//) was killed by the operation, and that the 

 intermediate region consisting of two thoracic segments and eight 

 abdominal segments continued to develop normally except for 

 the mechanical difficulties interposed by the killed material. 



15 



16 



FIG. 15. Side view of an egg of Leptinotarsa decemlineata three days old. 

 (L.D. 016 62). The anterior end (k) was killed when the embryo had reached the 

 stage shown in Fig. 4; the posterior end continued to develop, ab, abdomen; h, 

 head; t, thoracic appendages; //, tail fold. 



FIG. 16. As in Fig. 15, six days old (L.D. 016 BS). e, enteron; hi, hind in- 

 testine. 



An in toto preparation of an older embryo from this material 

 (Fig. 1 6) shows that the living part of the embryo succeeded in 

 growing around the yolk and developing a hind intestine (hi) 

 which grew forward toward the yolk-filled enteron (e). 



