1902.] Cerebral Commissures in certain Marsupialia. 



227 



The investigations for my memoir of 1894 were carried out chiefly 

 on the brains of Omithorfoynchus, Perameles, Trichosurus, and Macropus. 



Fig. 1. — Trichosurus vulpecula. The mesial aspect of the right csrebral 

 hemisphere, x 2. 



c.v 



cp.e 



Fig. 2. — Transverse section through the two cerebral hemispheres of the same in 

 the plane a, b (fig. 1). x 3. 

 c.d., commissura dorsalis. c.v., commissura ventralis. cp.e., capsula externa. 

 f.a.y fasciculus aberrans. 



In the^Monotreme and the smaller Marsupial {Perameles) the common 

 Mammalian relationship of the ventral commissure to the external 



R 2 



