TRANSPLANTATION OF THE SPINAL GANGLION 551 



The sections from the brain of Rat I containing a graft of 

 ten days' standing shows the spinal ganglion mibedded in the sub- 

 stantia alba just dorsal to the radiations of the corpus callosmn. 

 It is easily recognized by the abundance of connective tissue and 

 by the presence of the round or polygonal cells characteristic of 

 the spinal ganglion. These are arranged in the shape of a horse- 

 shoe, two or three cells deep, around the periphery of the gan- 

 glion on the side toward the corpus callosmn. All nerve cells have 

 disappeared from the interior of the ganglion. The surviving 

 cells are in various stages of chromatolysis, but the majority of 

 the cells show only partial solution of the tigroid masses. These 

 cells are much swollen and their nuclei are excentric. No small 

 nerve cells can be seen. These are more susceptible to injury 

 than the larger cells and rapidly disappear from the transplanted 

 ganglia. 



Substantially the same conditions are to be seen in Rat II, 

 also representing a ten-day graft. 



The spinal ganglion which was allowed to remain in the brain 

 for two months is shown in figure 1 . The graft was not as deeply 

 placed as the others, but was imbedded in the cortex near the great 

 longitudinal fissure and covered over by a prohferation of the pia 

 mater. The ganglion is much decreased in size and surrounded 

 by scar tissue. It contains only a small fraction of the number 

 of cells to be found in a nonxial ganglion, but these few cells are 

 of normal appearance, so far as can be ascertained by the carmine 

 stain. The shape and size of the cell body, the position, size 

 and contour of the nucleus and the absence of any proliferation 

 of the nuclei of their capsules justify one in assuming that these 

 cells are not undergoing degeneration but have survived the 

 transplantation and would continue to exist indefinitely in their 

 new position. 



A few medullated nerve fibers can be seen in the ganglion. 

 These are gathered together in a bundle which can be traced for 

 some distance in the scar when a series of these sections are 

 studied. It is not possible to say whether these are regenerated 

 fibers or fibers which have persisted from the time of transplanta- 

 tion of the ganglion. 



