RECAPITULATION OF THE NERVES. 267 



fibres in the manner typical for organs of the communis 

 system. 



II, — Recapitulation of the Nerves. 



The review of the components of the several nerves can 

 best be done graphically by means of the diagrams, Figs. 

 8 to 12. These diagrams are composites constructed from 

 a series of camera outlines of transections of the brain 

 running through the entire extent of the root area of the 

 nerve in question and are drawn with a uniform magnifi- 

 cation. They are somewhat schematic, but they are not 

 theoretical, as only the components which I have observed 

 in Menidia are included. They are, of course, far from 

 complete and other components than those figured are 

 doubtless present in many, if not all, of these nerves. 

 In reading the following pages these diagrams giving 

 projections upon the transverse plane should be compared 

 with the projections upon the sagittal plane made from 

 the same series of sections and given in Figs. 3 to 5. 



/. — T/ie Spinal Nerves. 



The diagram, Fig. 8, exhibits the relations as seen at 

 the level of the fourth spinal. The large ventral root 

 passes through the ganglion into each of the rami in the 

 typical manner. The dorsal root is very small, much 

 smaller, apparently, than the combined sensory compo- 

 nents of the rami which leave the ganglion. Fibres are 

 seen to pass from the sympathetic chain into each of the 

 rami. The ventral ramus is the largest and contains more 

 sensory than motor fibres. The ramus medius is rather 

 large and contains rather more motor than sensory fibres. 

 The two dorsal rami are both small. The cephalic one, 

 the r. communicans, is wholly sensory, the caudal one, r. 

 spinosus, is wholly motor. They both run bodily into the 



