THE EMBRYOLOGY OF THE EYE. 4 1 



rudimentary cornea. When the mesoblastic 

 cells first push In from the sides to form the 

 rudimentary cornea (Figs. 4 and 7), they have 

 an oval nucleus and a large cell-body with two 

 processes and occasionally more. In a vertical 

 section of the cornea the cells have a parallel 

 direction, and appear as separate bipolar cells, 

 In a flat section the processes extend in various 

 directions, and small offshoots from the pro- 

 cesses anastomose with those of other cells. 

 Very soon the cells become flattened. Then 

 in a vertical section of the cornea the nucleus 

 has a long spindle form, and the body of the 

 cell appears only as a long delicate process 

 from either end of the nucleus. In a flat 

 section at this stage we see a slightly oval 

 nucleus and a broad cell-body ending in tw^o 

 sharp processes. We now find delicate fibres 

 resting on the cells, appearing similar to the 

 delicate cell-processes as seen in a vertical 

 section. These fibres rapidly increase in num- 

 ber, separating the cells in a vertical direction. 

 The long processes of the cells finally become 



