214 THE OLFACTORY ORGAN, BY PROFESSOR BABUCHIN. 



to the central part of the olfactory organ is not less difficult to 

 answer. It has long been known, through the researches of 

 Walter (6), Leydig (7), Max Schultze (4), and has recently 

 been confirmed by Meynert (8), that the fibrils of the olfactory 

 nerve arise by fasciculi from the large spherical bodies which 

 are imbedded in the bulbus olfactorius. Still, as Kolliker 

 states in his work, the minute anatomy of these structures 

 has not been thoroughly investigated. The best results are 

 obtained by the investigation of their various relations in 

 Plagiostomata, where they possess the same constituent parts 

 as in the central apparatus of higher animals, though isolated 

 and far apart from each other. In the Torpedo, for example, 

 the bulbus olfactorius lies immediately upon the olfactory fossa, 

 and is united by means of the long and slender tractus 

 olfactorius with the olfactory lobes (?) (Scheinlappen), whilst 

 the sheath of the tractus is continuous with that of the bul- 

 bus, in which the above-named spheroidal structures are dis- 

 tributed without any definite arrangement. They are separated 

 from one another by nerve fibres and vessels, appear in the 

 form of a finely granular structure, and are apparently beset 

 externally with nuclei. In the Torpedo it may easily be 

 demonstrated that these apparent nuclei are unquestionably 

 very small cells, some of which are bipolar, whilst the majority 

 are multipolar. One of the processes of these cells is some- 

 times smooth, and runs towards the tractus olfactorius, where 

 it becomes invested with medullary substance. The other pro- 

 cesses are at first thick, but subsequently divide into an 

 infinite number of branches, which penetrate the spherical 

 corpuscles. In the bipolar nerve cells the more delicate pro- 

 cess passes into the tractus olfactorius ; but the other, which is 

 of distinctly fibrillar structure, penetrates into a spherical 

 body, where it breaks up into extremely fine fibrils. The 

 fibrils in some instances enter divergingly into a spherical body, 

 without any definite arrangement, and emerge again from one 

 side, united into a fasciculus ; in other instances they already 

 unite in the spherical body itself into a fasciculus which forms 

 a kind of spire or coil, and then associates itself with the 

 other fasciculi of the olfactory nerves (fig. 343). 



What morphological significance are we to attribute to the 



