360 P. R. BILLINGSLEY AND 8. W. RANSON 
tion over those which enter the ganglia by way of the white rami 
and truncus sympathicus. 
It is generally acknowledged, since the publication of Bidder and 
Volkmann’s paper, that an increase of nerve fibres takes place at the 
various ganglia. The nature of such increase is easily seen by the mere 
inspection of the nerves which are in connection with such ganglia as the 
superior cervical; the number of non-medullated fibres which pass out 
of it to proceed peripherally along the internal and external carotid 
nerves and along the peripheral grey rami communicantes of the upper 
cervical and lower cranial nerves is immensely greater than all the 
fibres both medullated and non-medullated which pass to it from the 
central nervous system along the cervical splanchnic (cervical sym- 
pathetic) nerve. So too the masses of non-medullated fibres which 
leave the semi-lunar ganglia to be distributed to the stomach, liver, 
intestines, ete., are very much greater than all the fibres contained in 
the rami afferentes of these ganglia. It is only necessary to picture 
to one self the number of fine medullated nerves contained in the various 
nerve roots, In comparison with the number of non-medullated fibres 
which pass out of the various ganglia of the body, to see what a great 
increase of nerve fibres must have taken place in the course of the 
nerves between the central nervous system and the periphery. Doubt- 
less such increase is partly to be accounted for by the direct division of 
non-medullated nerve fibres. Such division however takes place chiefly 
in connection with the passage of the nerve through a ganglion. 
It is obvious from all this that the impulses carried by one 
preganglionic fiber must be passed on to several postganglionic 
neurones. But no observations are furnished which would 
enable us to estimate the number. It would add precision to 
our conception of the interrelation of these neurones if a fairly 
definite numerical ratio could be assigned. 
The superior cervical ganglion offers a favorable field for the 
investigation of this question. As we have seen in the preceding 
paper, there is no reason to suppose that fibers enter it except 
those which ascend in the cervical trunk. Aside from a small 
peripheral bundle consisting chiefiy of unmyelinated fibers, the 
truncus just caudal to the ganglion consists of ascending myelin- 
ated fibers. These vary m size from 1.5u to 4.5y, i.e., are typical 
preganglionic fibers. In some specimens there are also a few 
fibers as large as 64 or 7u which might be interpreted as being 
sensory. But in the nerve counted, the largest fiber measured 
5y and only eight other fibers approached this in size. In this 
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