

MODE OF TERMINATION OF MOTOR NERVES IN VERTEBRATA. 209 



statements respecting the form that the process of the axis 

 cylinder possesses may be, the position which he ascribes to it 

 is, upon grounds that will hereafter be discussed, certainly sur- 

 prising. The method of staining with solutions of gold and 

 silver, which has been found so advantageous in other depart- 

 ments of the minute anatomy of the nerves, has up to the 

 present, so far as this question is concerned at least, yielded no 

 decisive results. 



From what has already been stated it may, however, be 

 maintained, in regard to the Arthropoda, that each of their 

 muscular fibres receives a great number of nerve ends ; that 

 the nerve sheath is continuous with the sarcolemma ; that the 

 proper conducting nervous fibre, that is to say, the axis cylin- 

 der, traverses the point of union of the two tubes, and divides in 

 the nerve eminence ; and that all nerve eminences possess at 

 their base a layer of protoplasmic muscle substance, that may 

 stretch to a variable extent into the contractile part of the 

 fibre. These results have been obtained from an examination 

 of the tissues in Hydrophilus piceus, Dytiscus marginalis, 

 Carabus auratus, Silpha obscura, Melolontha vulgaris, Geotrupes 

 stercorarius, Trichodes apiarius and alvearius, Musca domes- 

 tica, Tabanus bovinus, Bombus, Tegenaria, Argyroneta aquatica 

 and Astacus fluviatilis, and consequently in all three classes of 

 the Arthropoda, 



THE MODE OF TERMINATION OF THE NERVES IN THE 

 VERTEBRATA. 



A. Amphibia. The knowledge of the mode of termination of 

 the nerves in Amphibia, and especially in the Frog, is of great 

 interest, because these animals have for so long a period been 

 employed by physiologists as the subject of investigation in 

 regard to the relations existing between motor nerves and 

 muscles. The different muscles of the Frog which have been 

 particularly examined are the sartorius, the muscles of the eye, 

 the short fibres of the penniform gastrocnemius, and the small 

 muscles of the foot that lie between the toes. 



The uncontractile protoplasmic substance, or the remains of 

 it, in the muscles of Frogs, occupies as is well known, a very 



