DR. BEALE, ON THE TISSUES. 83 



dinal groove of the heart, and the grooves between the auricles 

 and ventricles, but many can be demonstrated over the 

 general surface of the ventricles. At short intervals bundles 

 can be seen to dip down in the spaces in which the vessels 

 also pass, and these from their transparency are soon lost 

 amongst the muscular fibres. Numerous microscopic ganglia, 

 resembling those of the sympathetic, are connected with 

 many of these nerve fibres. In some cases, collections of gan- 

 glion cells are seen at the side of the nerve fibre, and in 

 many instances two or three ganglion cells can be made out 

 in the very substance of the trunlc. These microscopic 

 ganglia are demonstrated without difficulty and in immense 

 number, in properly prepared hearts, but from the fact that 

 most of them are embedded in adipose and in areolar tissue, 

 they are very liable to be overlooked. They are most 

 numerous at the base of the heart in the grooves between the 

 auricles and ventricles, in the longitudinal grooves, and in 

 the areolar tissue at the base of the large arteries, and in that 

 surrounding the arteries themselves. 



In the muscular substance of the heart, the fine branches 

 of the nerves may be followed. Their general disposition 

 resembles that in voluntary muscle, and, as the nuclei of 

 the muscular fibres of the heart are in the very centre of the 

 fibre, there is no fear of mistaking these for the nuclei of 

 the nerve fibre. Many nerve fibres are distributed to the 

 vessels, but by far the greater number certainly ramify 

 on the surface of the muscular fibres. It is impossible 

 to demonstrate these latter points unless the vessels have 

 been, in the first instance, carefully injected with transparent 

 fluid. 



These preparations have caused the lecturer to differ from 

 the general opinions now entertained, with reference to the 

 nature of the so-called gelatinous, or gray, fibres. The dis- • 

 tribution of these fibres seen in the pericardium, their con- 

 nexion with the ganglia, their constant appearance, the 

 numerous nuclei connected with them, are all incompatible 

 with the notion of theii' consisting merely of bundles of con- 

 nective tissue. It can be shown that many of these fibres 

 are the only fibres connected with most unquestionable 

 ganglion cells, and those who still maintain such fibres to be 

 connective tissue, will. Dr. Beale thinks, find it very difficult 

 to accoimt for the presence of the ganglia in the number in 

 which they are found in connexion with this supposed 

 fibrous tissue. He holds with Remak, and with Todd and 

 Bowman, in this country, that these gray fibres are veritable 

 nerve fibres, and must be altogether removed from the con- 



