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with the lamina terminalis I thiuk the designation "Nervus ter- 

 minalis" is one that will fit all cases, and therefore, propose that 

 as a suitable name for this nerve. 



The anatomy and embryology of the "Nervus terminalis" as given 

 above, brings to the front several features of general interest. Its 

 marked individuality and separateness from the other cranial nerves 

 justifies calling it "a new nerve" and therefore, giving it a new name. 



In the Selachians, its close association within the main olfactory, 

 and its distribution within the olfactory cup, might give ground for 

 the suggestion that it is a radix mesialis of the olfactory nerve. This, 

 however, appears to me fanciful, as the nerve has no connection, at 

 any time of its growth, with olfactory glomeruli. Even if it be one 

 of the olfactory bundles in an unusual position, its method of origin, 

 and difference from all other olfactory radices would still justify the 

 use of the designation "new nerve". 



It is a relatively simple ganglionated nerve, that has apparently 

 undergone little modification. This, in itself, is a very notable cir- 

 cumstance, on account of its position on the brain in a region of ex- 

 treme modification. Since it has remained in a relative archaeic con- 

 dition, we may conclude that its function has not been greatly elabo- 

 rated. It may have been largely supplanted by the development of 

 the olfactory,, or some of the branches of the trigeminus. 



When all circumstances of its structure and development are 

 taken into account, it seems to me, not unlikely, that we have here 

 the remnant of a very ancient nerve, whose original function is un- 

 known, which in the process of development has been reduced to se- 

 condary rank, through the prodigious development of adjacent nerves 

 and brain territories. 



It has been shown that this nerve precedes the olfactory in em- 

 bryonic origin, but the assumption would not be justified on this 

 account, that it is, therefore, older in pbylogenetic history though such 

 may be the case. 



Its development in so many adult Selachians would indicate that 

 it is still functional though reduced to a subsidiary rank. 



Its ganglion will throw it among sensory nerves. The ganglion 

 is often in the form of a proximal and a distal portion as in the 

 IX. nerve. In fact, there are many resemblances between the "Nervus 

 terminalis" and the Glosspharyngeal. In front of its distal ganglion 

 there are two principal branches, and sometimes a third branch, which 

 reminds one of the pretrematic and posttrematic branches of the 

 cranial nerves in the region of the gill-clefts. 



