86 



Bjilletin of Laboratones of Denison University. [Voi.xiii 



Petromyzon ('02), though the secondary neurones of type I 

 were found about as in teleosts. It Petromyzon, it is interest- 

 ing to note in this connection, the cutaneous terminal bud sys- 

 tem is well developed. 



Fig. 2<). Transverse section through the vagal lobes of Ameiurusnebidos^is 

 illustrating a type II cell within the vagal lobe similar to those in Figs. 27 and 

 28 ; also two other small cells at the ventral angle of the fourth ventricle, whose 

 neurites terminates among the intermediary neurones of the same and opposite 

 side. One of the latter cells is impregnated ; also a ventral horn cell on the left 

 side. Two supporting fibers of the neuroglia system are shown on the right side. 

 GoLGi method. X 50. 



l.m., lemniscus; s.g.t., secondary gustatory tracts; sp.V., spinal V tract; 

 V. ventricle. 



The root fibers which end on the surface of the vagal lobe 

 spread out in very wide arborizations (Figs. 30 and 31). These 

 are most densely massed in two regions in intimate relation with 

 the two groups of chief secondary neurones already referred to 

 as the dorsal and lateral secondary gustatory neurones (Fig. 26). 

 The general relations of the two groups of superficial secondary 

 neurones are indicated in Fig. 31, where a dense neuropil richly 



