175 



he also took the roots of the N. Vomeronasalis to be those of the 

 N. Tenninalis. 



Regarding the mouse lie sajs "Die sog. mediale Riecinvnrzel von 

 der bereits Ca.tal, Kappers u. A. behau|)tet haben, sie sei nicht als 

 eigentliche Rieohwnrzel zii bezeiehnon, ist eine Wiii-zel des N. Ter- 

 minalis". No wonder that he continues "Sie hat bedeulende Beziehun- 

 gen zum Olfactorius". 



The second important ehicidation appeared, as has already been 

 said, in a communication, also in 1913, of Hubeh and Gtht.d, who 

 had come on this subject a propos of the work of Johnston, which 

 had partly been done in Huber's laboratory. 



These writers examined rabbit embryos by the silver-pyridine 

 method. They could fully confirm Johnston's results that the N. 

 Terminalis and the N. Vomeronasalis were two different nei'ves, and 

 that the ganglion and the disseminated ganglionic cells belong, not 

 to the N. Vomeronasalis, which is evidently a specialised bundle of 

 the olfactory nerve, but indeed to the N. Terminalis. 



While Johnston however was still of opinion that the periphei-al ter- 

 mination of the N. Terminalis was limited, principally in any case, to the 

 region of the N. Vomeronasalis, these investigators discovered that 

 this ending is to be found in the foremost part of the nasal septum, 

 reaching caudally to the rear border of the Organon Vomeronasale. 

 It is only a small part of the peripheral branches that reaches this 

 organ and the true olfactory mucous membrane, the region of the 

 fila olfactoria, was free from branches of the N. Terminalis. 



Through difference in tint the branches of the Terminalis could 

 well be distinguished from those of the Trigeminal nerve (Nasociliary 

 and Nasopalatine), which are also found in the mucous membrane 

 of the nasal septum. 



As will presently become clear, it is of importance in following 

 the nerve to Amphioxus, that the N. Terminalis does not branch in 

 the olfactory mucous membrane. 



In 19J2 and 1913 Mc. Cotter published his investigations on the 

 N. Vomeronasalis and the N. Terminalis. By means of the dissecting 

 microscope, thus as it were at magnifying glass magnification, he 

 found the latter in the adult dog and cat, but not in the rat, the 

 rabbit, the sheep, the guinea-pig or the oppossum. That he did not 

 find it is not to be wondered at considering his method. His opinion 

 that the N. Terminalis ends peripherally at or near the vomeronasal 

 organ is also comprehensible because the bundles here arc thicker, 

 the fibres of the N. Terminalis being strengthened by those of the 

 vomeronasal nerve. 



