Humphrey, Brain of the Snapping Turtle. 85 



are now clearly recognized as the posterior longitudinal fasciculi. 

 The reticular area formed by the lateral column and the ventral 

 cornu has greatly increased. Passing again cephalad (Fig. 12) 

 we see the same process continued. The dorsal column is still 

 changing shape, its mesal projection is less prominent and the 

 sulcus consequently shallower. The dorsal cornu is represented 

 only by a reticular area. The lateral column has crowded the 

 ventral cornu mesad from its natural position until the reticular 

 processes blend at the raphe with those of the opposite side ; a 

 nidus is formed at their junction. The posterior longitudinal 

 fasciculi are separated completely from the lateral columns and 

 have passed still farther dorsad, elevating the floor of the meta- 

 ccele and forming a wide shallow sulcus on either side. Fig. 1 3 

 shows a section still farther cephalad. In this the main relations 

 of the parts are as in Fig. 12, although the shifting process is 

 carried still farther. The lateral border of the metacoele has 

 become straightened, with a slight lophius (Sulcus a, Fig. 

 13) near the dorsal margin, formed by a division of the dorsal 

 column and the mesal projection of the dorsal portion. The 

 cinerea is still further limited in its area while the reticular 

 areas are greatly increased. From this section cephalad until 

 the region of the auditory nerve is reached no special difference 

 in the relation of parts is to be noticed. The shifting of parts 

 is continued, the small sulcus and lophius at a Fig. 13 disap- 

 pear. The area of the cinerea is lessened and the portion rep- 

 resenting the ventral cornu is pierced by a bundle of transverse 

 fibres. In the region of the 8th nerve (Fig. 14) the lateral 

 walls of the metaccele are thickened and brought nearer to- 

 gether making the sulcus at either side of the posterior longitu- 

 dinal fasciculus narrower and deeper, while the furrow between 

 these two bundles has deepened. The region of the lateral col- 

 umns becomes massive and the reticular areas are slightly re- 

 duced. A section at the origin of the fifth nerve shows the 

 lateral walls thinner ; the region of the lateral column retains 

 its massive character, while the entrance of the numerous fibers 

 of the 5 th nerve into the lateral part of this massive region 

 gives rise to a projection of the lateral surface at that point 



