282 



Frederick Tilney, 



a sagittal series of graphic reconstructions of the diencephalic floor 

 in the plane of the median line. In fig. 3, taken from a 7 mm cat 

 embryo, the floor shows no modification; caudad it rises abruptly to 

 the Sylvian aqueduct of the mid-brain. At the junction of the basal 

 and vertical lamina constituting the inter-brain floor, a slight caudal 



10 



Fig. 3. 



protrusion appears which indicates the inception of the infundibulum 

 and infundibular process. This protrusion in the 10 mm cat embryo 

 has increased so much as to give definite form to the above mentioned 

 structures (fig. 4). The first appearance of the ventro-cephalic pro- 

 trusion of the saccular eminence is seen in the 14 mm embryo. In 

 this stage the infundibular process has increased in size as a result 

 of a large cephalic projection. Growth in this line is apparently 



