GANGLIA. 425 



these capsules connective-tissue septa and trabeculae pass into 

 the interior of the ganglia, giving support to the nerve-elements. 

 The cell-bodies (ganglion cells) of the neurones constituting these 

 ganglia are arranged in layers under the capsule and in rows and 

 groups or clusters between the nerve-fibers in the interior of the 

 ganglia. More recent investigations have shown that several types 

 of neurones are to be found in the spinal and cranial sensory gan- 

 glia ; of these, we may mention the following: (i) Large and 

 small unipolar cells with T- or Y-shaped division of the process. 

 These neurones, which constitute the greater number of all the 

 neurones of the ganglia under discussion, consist of a round or 

 oval cell-body, from which arises by means of an implantation cone 



Fig. 339. Ganglion cell from the Gasserian ganglion of a rabbit ; stained in methylene- 



blue (infra vitant). 



a single process, which, soon after it leaves the cell, becomes in- 

 vested with a medullary sheath and usually makes a variable num- 

 ber of spiral turns near the cell-body. According to Dogiel, this 

 process divides into two branches, usually at the second or third 

 node of Ranvier, sometimes not until the seventh node is reached. 

 Of these two branches, the peripheral is the larger, and enters a 

 peripheral nerve-trunk as a medullated sensory nerve-fiber, termi- 

 nating in one of the peripheral sensory nerve-endings previously 

 described. The central process, the smaller of the two, becomes a 

 medullated nerve-fiber, which enters the spinal cord or medulla in a 

 manner described in a former section. The cell-body of each of 

 these neurones is surrounded by a nucleated capsule, continuous with 



