PLATE 3 
EXPLANATION OF FIGURES 
24 Transverse section of the same brain as shown in figure 23, through the 
interventricular foramen, showing the velum transversum and the beginning 
telencephalic choroid plexuses. 
25 Transverse section of the brain of a12-mm. Amblystoma larva through the 
interventricular foramen, showing the appearance of the diencephalic choroid 
plexus and the elaboration of the telencephalic choroid plexus. 
26 A similar section through a three-months-old larva, showing the eventual 
arrangement of the parts of the hemispheres and the relations of the choroid 
plexuses. 
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