is?6 MEDUS2E 33 



positive in describing a chain of cells running round 

 the inner part of the marginal canal. Now, although 

 I sometimes see a thin cord-like appearance here, I 

 should not dare to say it was nervous. Gold cer- 

 tainly stains it, but it also stains many other parts 

 of the tissue, and until I can see cells here I cannot 

 be sure about a visible nervous cord. The cord I do 

 see may be the wall of the marginal canal. I intend 

 to persevere, however, trying your suggestions, also 

 osmic acid. 



I can get no indications of electrical disturbance 

 during contraction in the way you suggest — at least 

 not with Sarsia ; but I intend to try with some of 

 the larger Medusae. 



Some, apparatus is coming from Cambridge to 

 enable me to test for electrotonus and Pniiger's law. 

 I shall apply it to the luminous Medusaa also, whose 

 light, I forgot to say, is seen under the micro- 

 scope in the dark to proceed not only from the 

 margin alone, but from that particular part of the 

 margin where Agassiz describes his chain of nervous 

 cells. 



Geo. J. Eomanes. 



From C. Darwin to G. J. Romanes. 



Down, Beckenham, Kent : July 18, 1875. 



I have been much interested by your letter, and 

 am truly delighted at the prospect of success. Such 

 energy as yours is almost sure to command victory. 

 The world will be much more influenced by experi- 

 ments on animals than on plants. But in any case 



D 



