41 



from any of the complex end-apparatus we have met with, but other- 

 wise they have every other characteristic. 



It is impossible to regard these cell appearing bodies as artefacts, 

 they being perfectly definite in outline and form, as well as being 

 stained intensely black by the silver which artefacts never are, these 

 latter being always of a more or less reddish color; and the only 

 question that could arise would be : if they are simply large nodosities 

 in the pathways of the sympathetic fibres? Their protoplasmic ex- 

 tensions are so different in size and irregularity of contour, and so 

 unlike, in general appearance, any of the surrounding neural fibres, 

 that we are forced to conclude, despite the non-appearance of nucleus 

 and nucleolus, that they are definite small nerve cells and not gan- 

 glionic swellings in the paths of the fibres. 



The presence of ganglion cells in the ventricular wall explains 

 very many enigmatical circumstances in the physiology of the heart's 

 action, especially the experiment of separating the lower two-thirds 

 of the ventricle from the upper portion, supplying it with blood through 

 a double canula, and causing spontaneous rythmical pulsations, or the 

 fact that isolated portions of the frog's ventricle will rythmically con- 

 tract for a long time after isolation from the body, on artificial stimu- 

 lation. 



July 15, 1893. 



Addendum. 



Later and more numerous sections from the ventricles of Mus 

 and Rana esculenta show in addition to the above histological ele- 

 ments a large plexus of coarse ganglionic thickenings among the nerve 

 fibres between the muscular bundles of the ventricle, which may be 

 likened to the plexus of Auerbach in the intestine, though the out- 

 lines of the ganglia are somewhat different. These ganglionic enlarg- 

 ments are connected with the filaments of the peri-muscular plexus 

 by rami, and from these extensions a considerable portion of this 

 plexus most probably has its origin, though the fibres that originate 

 in and among the vascular plexuses, are by no means of inconsiderable 

 number. Many of the ganglionic thickenings of the heart plexus have 

 a vacuolar spot in either their centre or thickest portion, which 

 probably represents an unstained nucleus. 



Some of the spindle cells about which we expressed distrust as 

 to their being undoubted nerve cells, have resolved themselves into 

 local enlargments of the fibres; but definite isolated nerve cells with 



