THE STRUCTURES AT THE BASE OF THE BRAIN. 



97 



structures which are there situated is known to us, let us turn a 

 brain bottom upward, and, having cleared away the pia mater 

 and blood-vessels, study the specimen carefully. 



The figure given later on (page 99) will serve as a guide. 

 First, we see the crura cerebri emerging from the mass of the 



Cerebellum. 



FIG. 55. 

 The ventricle opened from above. 



, Inferior horn. 



brain. Just in front of them, in the space which, in the cut, is 

 occupied by the optic nerve, lies the substantia innominate,, 

 which contains the ansa lenticularis and the inferior pedicle of 

 the thalamus. Previous frontal sections have taught you that 

 the white mass visible here is the pes pedunculi, which is the 



