Olfactory Apparatus in Dog, Cat and Man 35 



fibers could be traced for a considerable distance, and in some cases 

 fibers were traced nearly through the cribriform plate. The nerves 

 were not seen to bifurcate in the layer as described by Van Gehuchten 

 and Martin, but remained as individual fibers until near the glomerulus. 

 At their entrance into the glomerulus they divide and subdivide to form 

 many branches which interlace but do not anastomose with the other 

 fibers found there. In some cases four or five of these axones were 

 traced into the same glomerulus (Fig. 47). 



The glomerulus of the olfactory bulb is formed by the interlacing of 

 branches from the axones of olfactory cells and the dendrites of the 

 mitral cells of the olfactory bulb (Figs. 48-53). (For clearness these 

 have been shown in separate drawings, that is, axones of nerve cells and 

 dendrites of mitral cells are not shown in the same figure.) A glo- 

 merulus may be formed by the interlacing fibers from one axone (Fig. 

 46), and from one dendrite (Fig. 50), or from several axones (Fig. 47), 

 and several dendrites (Fig. 52). While each axone comes from an 

 individual olfactory cell, the dendrites may come from a single or 

 several mitral cells. 



In the cat three dendrites from difl^erent mitral cells were found in 

 one glomerulus (Fig. 53). Fig. 51 shows .three dendrites from at least 

 two difi^erent cells. Fig. 53, two dendrites from the same mitral cell. 

 The branching of a single dendrite to different glomeruli was not seen. 



In the dog, dendrites from several different mitral cells were traced 

 to a glomerulus (Fig. 49), and a single dendrite was seen to branch to 

 three different glomeruli (Fig. 48). 



In man the olfactory bulb has been studied only in gross preparations. 

 The olfactory nerves were traced through the cribriform plate to the 

 outer layer of the Inilli. The histology of the olfactory bulb was not 

 studied, but is given by all authors. The glomeruli are formed by an 

 interlacing of the axones of the olfactory cells and the dendrites of the 

 mitral cells, as in lower animals. 



DlSTEIBUTION OF THE OTH ISTeRVE TO THE NoSE. 



The nose is innervated by branches of two divisions of the 5th nerve. 

 The anterior ethmoidal (nervus ethmoidalis) of the ophthalmic aiid 

 the spheno-palatine (nervii spheno-palatini) of the maxillary division. 



In the orbit the anterior ethmoidal nerve passes between the muscles 

 of the eve and enters the cranial cavity through the anterior ethmoidal 



