70 [May 1, 



certain reagents, such as acetic acid, they exhibit a precipitate of 

 fine sparse granules in their interior, as Kiihne has also observed ; 

 although when examined in the fresh state, or after being treated 

 with hydrochloric acid, or artificial digestive fluid, they appear 

 pellucid and uniform throughout. It is further worthy of remark, 

 that whilst the pale fibres are for the most part rectilinear prolonga- 

 tions of the dark-contoured fibres, instances occur in which a dark 

 fibre ends by dividing at once into two or three pale fibres. More 

 remarkable still are the cases in which a pale fibre comes off laterally, 

 and sometimes at right angles from a dark fibre, or where two pale 

 fibres come off together from opposite sides ; because such cases, 

 which Kiihne appears not to have seen, or at least has not represented, 

 are well calculated to show that the pale fibres are furnished with a 

 prolongation of the membranous sheath. 



The next question of interest arising from Kiihne* s observation 

 refers to the bodies which he looks upon as peculiar terminal organs, 

 and names the terminal nerve-buds. As regards these corpuscles, I 

 must confess that, after the most careful investigation, I have failed 

 to discover that they possess the peculiar internal structure which 

 Kiihne assigns to them. Considering the skill and address in 

 microscopic investigation which Kiihne has evinced in his inquiry, 

 and feeling persuaded that he must have met with what seemed 

 to him sufficient indications of the structure he has described, I 

 bestowed the greatest pains on the examination of these so-called 

 end-buds. I studied them in muscles and muscular fibres, both fresh 

 and treated with reagents. I employed the same magnifying powers, 

 and equally good lenses ; but the only conclusion to which I could 

 arrive is, that the corpuscles in question are nothing but ordinary 

 nuclei connected with the membranous sheath of the pale nerve-fibres, 

 not essentially differing from those found attached to the sheath of 

 the dark-contoured fibres from which the pale fibres are derived. It 

 is true that some of them show a dark streak in the middle or 

 towards the border, which at first sight might suggest a peculiarity 

 of structure ; but the appearance is obviously due to a fold or crease 

 on the surface, and the same thing is seen in the undoubted nuclei 

 of the dark-contoured fibres. Their shape, position, and relative 

 size may be judged of from the figures I have given ; and I have only 

 further to remark, that in fresh preparations they are usually very 



