86 DR. BEALEj ON THE TISSUES. 



from those in the more central part of the bundle. Dr. Beale 

 remarked that the formed material of these marginal elementary- 

 parts presents the appearance of ordinary fibrous tissue. A 

 corresponding fact is observed with regard tothe bundles of gray 

 nerve fibres. The nuclei situated at the outer part of the 

 bundle do not produce nerve fibres, but they give rise to the 

 formation of a kind of connective tissue only. Up to a cer- 

 tain period of their existence nerve fibres might have been 

 produced, but as a sufl&cient number had been developed, 

 these marginal cells degenerated and led to the production 

 only of a low form of tissue. 



It has been shown that fibres of connective tissue are very 

 often connected with the terminal branches of nerve fibres, 

 this is especially the case in old tissues which are abundantly 

 supplied with nerves. This point can be demonstrated in the 

 frog's tongue to such an extent that it would not. Dr. Beale 

 thinks, be possible to pronounce in certain cases, if a given 

 fibre were in a state of functional activity as an integral part 

 of the nervous system, or were merely a degenerated nerve 

 fibre no longer active, and consisting of what might fairly be 

 termed a form of connective tissue. The question can, how- 

 ever, always be determined by the presence or absence of the 

 little oval nuclei or masses of germinal matter. 



In many instances Dr. Beale has proved that these fibres 

 in connexion with active nerve fibres were not acted upon by 

 acetic acid, and beneath the plexus of nerves on the surface 

 of the mucous membrane of the epiglottis, were numerous 

 parallel fibres exhibiting the reaction and general characters of 

 yellow elastic tissue, and amongst the undoubted nerve fibres, 

 were fibres of the same description destitute of nuclei. Similar 

 appearances have been observed in the papillae of the human 

 skin and tongue. It would seem, then, that by the alteration 

 of nerves and capillary vessels, certain forms of ' connective 

 tissue ' are produced, and this has been observed in many 

 different situations and in difierent animals, man, mouse, cat, 

 frog, and others. 



In the dura mater, the coats of small veins have been seen 

 gradually thickening, until they were converted into solid 

 bundles of fibrous tissue, and many have been observed with an 

 exceedingly narrow cavity in the centre corresponding to the 

 calibre of the vessel. 



The alteration of nerve fibres into fibrous tissue has been 

 very carefully watched in many localities. In the human 

 organism the sole difficulty in following out the distribution of 

 the nerves arises from this cause. Fibrous tissue also forms 

 the remains of any other structures, in fact, the variety of 



