468 



L. S. STONE 



Fig. 54 Camera-lucida drawing, showing by dotted line extirpated area of 

 ectoderm one day after operation. The operation was done at stage 25 and in- 

 cluded auditory and preauditory placodes as well as epibranchial placode of VII. 

 X 10. 



Fig. 55 Camera drawing of embryo shown in figure 54 twelve days later, 

 showing extent of area of implanted blue ectoderm and absence of supra-orbital 

 line. X 10 



Figs. 56 a and b Lateral views of a reconstruction of the V and VII ganglionic 

 complex of animal figured in 55, showing respectively, the normal and operated 

 sides. The operated side shows a small VII lateral-line ganglion as only repre- 

 sentative of VII. There is also no gasserian ganglion on operated side. X 50. 



Fig. 57 Frontal section, showing only a small VII ganglion after removal at 

 stage 26 of an area of ectoderm similar to that shown in figure 54. X 37. 



