190 Messrs. Hancock and Embleton on the Anatomy o/Eolis. 



dular apparatus. We cannot confidently say that we have traced 

 groups of these pedicles into the nerves that issue from the gan- 

 glia, but we have seen what inclines us very strongly to the idea, 

 that such is in reality the relation of these two parts of the ner- 

 vous system. At PL VI. fig. 2, where a nerve b is shown coming 

 off from a buccal ganglion a, parallel strise are observed distinctly 

 passing towards the nerve from the interior of the ganglion. 

 Again, when the connexions of the nerves with the cerebral 

 ganglia are examined, parallel strise can be seen continued from 

 the commencement of the nerve for some distance into the gan- 

 glion, becoming gradually more and more obscured by the vesi- 

 cles of the ganglia and then lost altogether ; but from the tough- 

 ness of the enveloping membrane — the body of the Nudibranch 

 having lain for some time in spirit and water — and the extraor- 

 dinary delicacy of the contained parts, we have not been able to 

 lay bare, and leave in situ, in one and the same specimen, the 

 real connexion which we believe to exist between the nerves and 

 the vesicular element of the central ganglia. But w^e hope that 

 further observation will enable us to show that the pedicles of 

 the nerve-corpuscles in Eolis are continuous with the nerves; 

 and if this be so, then that it may be the means of illustrating 

 more clearly the connexion that exists in the Vertebrata and in 

 Man between the nerves and the white and the gray matter of 

 the brain and the rest of the centres of the nervous system. It 

 is highly probable, however, that all the cells of the ganglia pos- 

 sess a pedicle or stalk in their perfect state, and that the appa- 

 rent absence of a pedicle or pedicles in some cells or groups of 

 cells may be owing either to the unfavourable aspect under which 

 they are presented to the eye — they being so placed that the pe- 

 dicle is either very much foreshortened or hidden altogether by 

 the cell itself, or else to the pedicle having been broken ofi" du- 

 ring the manipulation of the specimen, or again to the magni- 

 fying power in some cases not being sufficient to make them 

 discernible, or lastly to their imperfect state of development. 



These cells or vesicles of the nervous ganglia of Eolis, although 

 they show only one cauda or prolonged pedicle, are doubtless 

 analogous to those caudate vesicles or nerve-corpuscles which are 

 characteristic of the gray matter of the cerebro- spinal and sym- 

 pathetic ganglia of the higher animals. 



The nerves themselves appear to have none of the cells above 

 noticed, but to consist of series of parallel granular lines or 

 fibrillse, which on tearing the nerve across often remain detached 

 from each other, and which are all in their perfect state enveloped 

 in a strong common sheath continuous with the membranous 

 capsules of the ganglia. Where a nerve gives ofi" branches, lines 

 of granular matter, probably the fibrillae just mentioned, are 



