Strong, Johnstoyt on Ncn'es of tJie Sturgeon. 173 



ser than in Teleosts and is composed chiefly of the root fibers 

 of the dorsal Vllth." which enter it and turn caudad, John- 

 ston very properly recommends that the name lobus trigemini 

 be entirely dropped. It is amusing that all recent writers are 

 agreed that the one nerve with which either species of " lobus 

 trigemini " has nothing to do is the trigeminus. 



The destination of the neurites of the Purkinje cells of the 

 cerebellum was not determined but it is considered probable 

 that they run through the acusticum to the base of the medulla. 

 The fibers entering the cerebellum come chiefly from the med- 

 ulla, the tectum and optic thalamus, also from the lobi inferiores. 

 Johnston emphasizes the structural continuity of the cerebellum 

 with the acusticum and is of the opinion that this fact points to 

 the conclusion that the cerebellum is the enlarged anterior end 

 of the center for the sensory nerves of the integument. 



The facts above mentioned in connection with the cranial 

 nerves lead Johnston to agree with Kingsbury in his analysis 

 of the sensory centers in the main, but, in view of the partial 

 mingling of the V-VIII-lateral line group in the medulla, to 

 think that Kingsbury separates the spinal Vth. and the cere- 

 bellum from the acusticum more than is warrantable. On the 

 other hand, Johnston emphasizes the distinction between the 

 centers for the above group and the center — the lobus vagi — 

 for the VII-IX-X group. After a brief consideration of the 

 peripheral structures innervated by these nerves, he comes to 

 the conclusion that "all sensory structures of ectodermal origin 

 are supplied by components of the Vth. (including spinal Vth. 

 components running in other nerves), Vlllth., and lateral line 

 nerves, and that all fibers supplying such structures have their 

 central endings in the nucleus funiculi, the ,tuberculum acusti- 

 cub, or the cerebellum, except such as pass through the acusti- 

 cum as arcuate fibers. On the other hand, all sensory struc- 

 tures of entodermal origin are supplied by Vllth., IXth. and 

 Xth. components, and all fibers supplying such structures find 

 their central endings in the lobus vagi." 



In coming to this general conclusion the writer appears to 

 have overlooked the important fact, which seems to be quite 



