034 LECTURE XH. 



with these states a diminished or increased supply of 

 blood to a considerable district, takes place. 



If now we return from this digression to our real sub- 

 ject, you will recollect that I had described to you my 

 ignorance concerning the real mode of termination which 

 the nerves have in the tactile bodies. Whether the 

 nerve ultimately forms a loop, or in any manner directly 

 terminates in the internal substance of the body, is not, I 

 think, as yet absolutely decided. 



If now we consider other instances of the terminations 

 of nerves, nowhere does any probability manifest itself 

 that they really do form loops. In every case in which 

 more certain knowledge has been acquired, the proba- 

 bility has on the contrary always become greater, that the 

 nerves either terminate in a large plexus or recticular 

 expansion ; or that they end in special apparatuses, con- 

 cerning which it is still doubtful whether they are pecu- 

 liar processes of a particular shape, into which the nerves 

 shoot out at their extremities, or whether they consti- 

 tute peculiar parts, non-nervous in their nature, to which 

 the nerves attach themselves. This latter mode of ter- 

 mination is, it would appear, characteristic of most of the 

 higher organs of sense, but in no single instance, in con- 

 sequence of the extreme difficulty which the investigation 

 of these parts presents, have any views been proposed 

 which have met with universal assent. Notwithstanding 

 the numerous investigations into the structure of the 

 retina and cochlea, the mucous membrane of the nose 

 and mouth, that have been made in the course of the last 

 few years, it must be confessed that the ultimate points 

 of histological detail have not as yet been altogether 

 satisfactorily settled. In nearly all cases there remain 

 two possible ways in which the nerves may terminate. 

 According to some their terminations are connected with 

 special structures which, according to the language 



