HaHa 



Fig. 8. — First abdominal ganglion of the ventral nerve-cord of Astracus 

 fluviatilis. Living tissue stained with methyl-blue. Nervous tissue only is 

 stained. Signiflcance of large fibers Rf not understood, m n o, Single cell from 

 the ganglion. Periphere nerven, Peripheral nerve. Einzelne Zelle aus dem Gang- 

 lion, a single cell from the ganglion. Further description in text. (After Retzius.) 



