362 Litteraturübersicht. 



In many preparatioiis each nerve seems to terminale in a loop, 

 while in otliers the terminal branclies seem to form a network." 



„What becomes of the axis cylinder, I have been unable to 

 make out. Whether the axis cyhnders terminale abruptly in 

 minute swelhugs, or form a network so dehcate that it escapes 

 detections, I am not in a position to say. There seems no doubt, 

 however, that the terminal twigs of the nerves form immediately 

 in front of the electric laj'er a nearly regulär series of loops. 

 These loops, which are very characteristie, stand at nearly right 

 angles to the surface of the diso; as the terminal twigs reach 

 the nervous lamina, the protoplasm is, as it were, heaped up 

 around the axes cylinders thus forming an almost continuous 

 series of minute cones. 



In oblique and sometimes in horizontal sections of the discs 

 the anterior surface of the electric layer presents a pitted appear- 

 ance, the margins of the pits suggesting a delicate network. 

 These shallow depressions which Ue between the terminal nerve- 

 fibres may result from the heaping up of the protoplasm of the 

 nervous lamina around the limbs of the terminal nerve-loops. 

 In conclusion, I need only add that every part of the electric 

 layer is equally rieh in nerves — everywhere all over the surface 

 the extremely delicate terminal loops are equally abundant. 

 There is no other organ, as far as I am aware, in which it is 

 so easy to demonstrate the presence of a countless number of 

 nerve-fibres terminating in a thin layer of protoplasm." 



Auf Tafel 28 in Fig. 14 und 14 a der letzten Abhandlung 

 (26) und auf Tafel 68 in Fig. 5 der zweiten Arbeit (24) sind 

 diese vermeintlichen „loops" dargestellt. Man sieht in diesen 

 Figuren, dass die letzten Nervenzweige hier übergehen in eine 

 einfache der vorderen „granulierten" Schicht dicht anliegende 

 Reihe etwas unregelmässig geformter Ringe oder Ösen, deren 

 jede eine kleine Öffnung begrenzt. Die Ringe sind senkrecht 

 zur Oberfläche der „granuherten" Lage gestellt. Das wäre so- 



