1862.] 139 



Conclusions. 



1 . In certain muscles of the frog the distribution of dark-bordered 

 nerve-fibres is pretty uniform in every part. Although in the case of 

 the pectoral a greater number of nerve-fibres is distributed to the 

 central part of the muscle, fibres may be traced from the large bundle 

 almost to the extremities of some of the muscular fibres. Many 

 branches which easily escape observation pass between the muscular 

 fibres, and their subdivisions supply neighbouring fibres, or are 

 gradually lost in the connective tissue. 



2. Fine nerve-fibres are most easily demonstrated on the external 

 surface of the sarcolemma near the nerve-trunks ; but reasons have been 

 advanced in favour of the conclusion that every elementary muscular 

 fibre is more or less freely supplied with nerve-fibres throughout its 

 entire length. Many of the fine nerve-fibres on the surface of the 

 muscular fibres become gradually very faint, until from their extreme 

 tenuity we are no longer able to follow them. 



3. Fine nerve-fibres in direct continuation with the dark-bordered 

 fibres, and less than the 30 / 000 th of an inch in diameter, have been seen 

 to divide into finer branches which have nuclei in connexion with them. 



4. The pale fibres delineated by Kuhne and Kolliker, and by them 

 considered terminal, consist of 



a. Fibres about the 3 * O th of an inch in diameter, or less, 

 resulting from the subdivision of the dark-bordered fibre. 



5. Fibres resulting from the subdivision of fine nerve-fibres 

 ramifying in the sheath of the dark-bordered fibre, or situated 

 external to it. 



5. Nuclei are found in connexion with 



a. The dark-bordered fibre itself, near its terminal ramifi- 

 cations. 



b. The fine fibres which are the direct continuation of the 

 dark-bordered fibres. 



c. The fine fibres in the sheath, or external to it. 



6. The nuclei and delicate fibres above referred to are arranged so 

 as to form networks, the meshes of which vary much in size, situated 

 with the capillaries on the external surface of the sarcolemma. The 

 fibres of this network are compound, and consist of finer fibres which 

 are distinct from, and do not anastomose with, each other. The fine 

 fibres continued from some of the dark-bordered fibres, as well as 



