182 THE COURSE AND DISTRIBUTION OF NERYE FIBRES. 



base of the peripheral organs of taste the nerve fibres 

 have been actually seen to pass in opposite directions, 

 Plate II, fig. 1, and in the so-called end organs of 

 muscles, Lecture XI, I have demonstrated two or more 

 fibres in numberless instances. The evidence that I 

 have brought forward in favour of the conclusion, 

 that nerves form continuous and uninterrupted cords 

 with bioplasts in their course, and continuous with 

 the matter of which the fibre is composed, cannot, 

 I think, be controverted or explained away, though 

 I dare say few will be disposed to accept my conclu- 

 sions just yet. 



239. The coHPse and distribution of nerve 

 fibres. — As already stated, all my observations tend 

 to the inference that nerves never end, and I think 

 that the concliTsions that have been arrived at in 

 favour of the idea of terminal extremities and ter- 

 minal organs have resulted from the examination of 

 inconclusive specimens or from erroneous observation. 

 A careful consideration of the facts observed concern- 

 ing — 1, the structure of certain peripheral organs 

 favourable for investigation ; 2, the distribution of 

 nerve fibres in nerve centres ; and 3, the connection 

 between the fibres and central nerve cells, forces upon 

 my mind the conclusion that the nerve fibres composing 

 the nerve trunks, and those finer branches which unite 

 to form dark -bordered nerve fibres, may be arranged 

 in the following siibdivisions, according to their 

 distribution : — 



1. Nerve fibres passing towards a centre — Afferent 

 fibres. 



2. Nerve fibres passing from a centre — Efferent 

 fibres. 



3. Nerve fibres connecting nerve centi-es with one 

 another — Gomviissural central fibres. 



4. Nerve fibres connecting the peripheral ramifica- 

 tions of nerves and peripheral nerve organs with one 

 another — Commissural per inhered fibres. Plate II, fig 1 . 



