204 



THE HEART. 



giving off, from time to time, branching collaterals. Both collaterals and axones 

 appear to pass out of the cord, into the lateral plexus. 



The axial portion of the cord also contains irregular masses of neuropile, 

 but whether they are derived from the axones of the giant cells, or from those of 

 the multipolar ones, or from both, could not be certainly determined. When too 



FIG. 117. Diagram illustrating the distribution of the cardiac neurones and their probable relations to the 

 branchial and vagus neuromeres. The heart and the nerve cord are shown projected onto the same plane 

 Vag. D., vagus division; BY. D., branchial division of the heart. 



many fibers are not colored, one may see irregular baskets of intertwining fibrils 

 at frequent intervals all through the thicker parts of the cord, and in the larger 

 strands of the plexus, n.p. Some are apparently free terminal arborescences, 

 others form a basket work around the body of the giant cells; or several multi- 



