ABBREVIATIONS 



a.o.j adhesive organ 



hyp., hypophysis 



hyp.p., hypophysial pit 



inf., infundibulum 



n.p.ep., vestigial epithelial lobe (parsepi- 



thelialis) 

 n.p.n., new neural lobe 

 o.p., olfactory placode 



op.v., optic vesicle 

 ot.v., otic vesicle 

 p./., pituitary floor 



p.g., pars glandularis of the hypophysis 

 p.i., pars intermedia of the hypophysis 

 /'."., pars neuralis of the hypophysis 

 t.p.f. thickened portion of pituitary floor 

 /, II, III, branchial arches 



PLATE 1 



EXPLANATION OF FIOURES 



11 A 4-mm. frog larva (R. boylei) showing the surface characteristics at a favor- 

 able stage for epithelial hypophysectomy. (a) Ventrolateral, (b) ventrocephalic 

 view. 



12 A median sagittal section of a frog larva of approximately the same age and 

 size as shown in figure 11. 



11 1 



