PLATES 4 



EXPLANATION OF FIGURES 



31 Medial view of a model, Stage IX. X 88. 



32 Lateral view of same. X 88. 



33 Medial view of a model, Stage XI. X 75. 



34 Lateral view of same. X 75. 



REFERENCES 



ch., optic chiasma op. s., optic stalk 



e-p., epiphysis par., paraphysis 



di. mes. /., di-mesencephalic fold p. c, posterior commissure 



hyp., hypophysis v. t., velum transversum 



m. cbl.f., mesencephalic-cerebellar fold 



548 



