184 Journal of Comparative Neurology. 



vorhanden sein, welche Goldsalze in derselben Weise reducirt, 

 wie die intravaginalen Nerven. Durch vveitere Behandlung der 

 Goldpraparate mit Cyankali gelingt es den sicheren Nachweis 

 zu fiihren, dass zwischen den intravaginalen Nerven nnd diesen 

 Sprenkelungen directe Continuitatsbeziehungen existiren." 

 This view is defended by Gerlach in his second communication 

 based on observations made with methylene blue. It would 

 seem to us, from Gerlach's descriptions and figures, that both 

 in his gold chloride and in his methlyene blue preparations, he 

 has stained the sarcoplasma, in which, as we believe, the axis 

 cylinder terminates. But the mere fact that, in methylene blue, 

 for instance, certain granules and other substances are tinged 

 blue, is not proof positive that these are of a nervous nature ; 

 as it is well known that, under certain circumstances, elements 

 other than nerve fibers are stained in methylene blue, even when 

 the blue is injected into the circulation of a living animal. 

 Red blood cells may be stained blue or show blue granules; con- 

 nective tissue cells ; intracellular cement substance; and now and 

 then most clearly yellow elastic fibers may in this way be stain- 

 ed. In well stained motor endings, before fixing or after fixa- 

 tion in ammonium molybdate, when examined under the 1-12 oil 

 imm., not a trace is seen of Gerlach's "intra vaginal network" 

 in methylene blue preparations. Dogiel discusses this point in 

 the following words : "Bei einer gehorig gelungen Tinction 

 normaler Muskelfasern ist nichts derartigen zubemerken." 



As our observations pertain exclusively to the ultimate 

 ending of the motor nerves in striped muscle, and, as our pre- 

 parations were made with that end in view, we do not desire 

 here to touch on the general distribution of the motor fibers in 

 striped muscles, on their branching, etc. For answering these 

 questions surface preparations are far more suitable than sec- 

 tions. Our observations admit, we believe, of our drawing the 

 following conclusions as to the structure of the motor endings 

 in striped muscle in the vertebrates examined, and we would 

 venture to suggest that such conclusions apply equally well to 

 motor endings of such other vertebrates as show a structure 

 similar to those here discussed. 



