MY PREDECESSORS. 397 



found the existence of granular nerves stated as a fact, 

 though without specific information either respecting 

 their discoverer or the animals in which they existed ; 

 and without a hint of any physiological significance in 

 the fact.* On my return home I made diligent search, 

 and by means of Canstatt's Jahresherichte for 1854 

 (p. Q6), learned that Meissner had discovered granular 

 trunks in the thread-like tiny worm Mermis ; and H. 

 MUller and Gegenbaur in the naked gasteropod Phyl- 

 lirJioe. 



On procuring the memoirs referred to,-(- I found the 

 fullest confirmation of my own observations, but no 

 appreciation of their physiological significance. Miiller 

 and Gegenbaur say : " Distinct fibres are not discover- 

 able in the trunks, which appear to consist of nothing 

 but a clear granular streaky substance (aus einer hellen 

 feinhornig streifigen Suhstanz). In some instances 

 there were small groups of ganglionic cells.'' And this 

 is all they remark. 



Meissner's observations are given in greater detail, 

 and appear to have suggested doubts, as analogous ob- 

 servations did to me. " The four trunks," he says, 

 " which issue from the ganglia have at first a clearly 

 fibrous structure, so that at the torn ends single 

 fibrillse appear ; but these fibres in their course soon 

 melt into a homogeneous band in which no trace of 

 fibre remains." Curiously enough, the branches given 



* Leydig, Histologie, pp. 59, 185. " Die Nervensubstanz ist ent- 

 weder mehr homogen und molekular, oder mehr von faserigem Aus- 

 sehen." 



f See SiEBOLD a. KoLLIker's Zeitsclirift f. Wissen. Zool., v, p. 233, 

 360; and vii. 99. 



