14. H. BERKELBACH VAN DER SPRENKEL 
the totality of its center is called the communis gray, which 
expression means that it is in general difficult, if not entirely 
impossible, to separate the two sorts of fibers in it (see, however, 
below). 
From this lobus facialis, especially from its dorso-medial pe- 
riphery where a great many of the capsular fibers end, a great 
number of secondary fibers arise (figs. 8 and 9), constituting the | 
anterior secondary gustatory tract already often mentioned. 
This tract is located near the descending V and runs chiefly, if 
not entirely, in a frontal direction following the spinal V tract, 
and ascending, when the latter has left the bulb, in a fronto- 
dorsal direction to the so-called Rindenknoten (Mayser), or 
anterior secondary gustatory nucleus. 
Apart from these fibers, Herrick has described descending 
gustatory fibers which do not originate from the dorso-medial 
periphery of the lobus VII but from the lateral part and descend 
along the spinal V tract. I do not doubt the existence of this 
bundle in Silurus, but have not been able to trace it from its 
‘origin. The fact that an area of fibers resembling in aspect and 
position those of the anterior gustatory tract continues also 
backward to the more caudal levels of the oblongata, even 
beyond the calamus, speaks in favor of their presence also in 
my object. 
Although the gustatory character of these two systems cannot 
be proved with exactness, there is much in favor of the names 
applied by Herrick, because these fibers originate from the periph- 
eral part of the lobus, in which are the terminals of the capsular 
fibers whose numbers are augmented, as stated above, when the 
number of taste buds is increased. Another reason is that these 
tracts themselves augment with the multiplication of taste buds. 
These tracts, or rather the correlative gray matter which 
accompanies them, determine the position of the motor V and 
VII nuclei, which acquire a ventral position where these tracts 
are highly developed, as in cyprinoids and siluroids, and remain 
more dorsal where these systems are poorly developed, only 
sending dendrites in their direction. Since in cyprinoids (Tinea) 
and siluroids these gustatory systems are enormously increased, 
