4 1)15. UEALK^ ON THE TISSUES. 



the distriliiition of nutrient matter. Over and over aj^aiii, 

 the imclci amongst the fibres of yellow elastic tissue have 

 been stained with carmine^ while not a single fibre exhibited 

 the slightest alteration. Dr. Eeale does not think, therefore, 

 that these fibres at any period of their existence, have any 

 such office as that of distributing nutrient fluid to the tissues 

 in connection with which they are found. 



Dr. Beale would bring forward evidence to show that 

 many tissues which, after having existed in a state of func- 

 tional activity for a certain time, waste and disappear, leave 

 behind a certain quantity of transparent fibrous tissue, which 

 is not completely removed by absorption. If muscle or nerve 

 waste from any cause, a structure somewhat resembling white 

 fibrous tissue remains behind, and in some cases a similar 

 structure occupies the situation which was filled by a vessel 

 at an earlier period. Dr. Beale desired to draw attention to 

 the cord-like network of fibres in connection with the ex- 

 ternal coat of a small branch of artery. The specimen is 

 taken from the abdominal cavity of a frog ; a is the outer 

 part of the muscular coat of the artery. A bundle of nerve 

 fibres is seen running in the external coat of the artery, and 

 at c some of the fibres are seen to leave the large trunk of 

 the nerve and run in the central part of some of the fibrous 

 cords. In another specimen a portion of one of these cords 

 with most distinct nerve fibres was seen magnified 700 

 diameters, and a transition may be traced from most un- 

 doubted nerve fibres to the very narrov/ branching fibres seen 

 in the upper part of the specimen. These fibres are not 

 altered by acetic acid, but by careful examination it is clearly 

 proved that they may be split up into finer fibres if they are 

 not actually composed of several minute fibres collected 

 together. They somewhat agree in character with the axis 

 cylinder of a nerve fibre. Some of the finest of these cord- 

 like fibres of connective tissue seem to consist of a trans- 

 parent matrix, in which two or three nerve fibres are em- 

 bedded. The transparent matrix is the so-called tubular 

 membrane of the nerve fibre. Dr. Beale believed that the 

 nuclei and delicate fibres continuous with them, embedded 

 in a more or less fibrous connective tissue, are nerve fibres 

 which were functionally active at an earlier period of life, and 

 that the matrix in which they are embedded corresponds to 

 the so-called tubular membrane. 



There are in different parts of the frog, especially in con- 

 nection with the skin and areolar tissue beneath, cord-like 

 fibres very much resembling those just described in their 

 general appearance, but differing from them in the disposi- 



