348 PROCEEDINGS OF THE OHIO ACADEMY OF SCIENCE. 



Upon the neuron theory is based the science of modern 

 neurology, in the upbuilding of which American investigators 

 have taken such a prominent part, and in which the work of 

 Brookover, Coghill, Herrick, and Landacre may well give the 

 Ohio Academy a special interest. That monumental record of 

 neurological work, the Journal of Comparative Neurology, is 

 also originally an Ohio product and was published in the state 

 until 1907. 



The keynote of modern neurology is the physiological analy- 

 sis of nervous structure. To some of us the cranial nerves are 

 mainly familiar through the classical mnemonic concerning 

 "Monadnock's peaked tops" and the hop-gathering "Finn and 

 German". These nerves, and the spinal nerves as well, the 

 modern neurologist analyzes into their functional components, 

 — somatic afferent and visceral aft'erent, somatic efferent and 

 visceral efferent; each of these classes is again separated into 

 general and special, and indefinitely further subdivided. (When 

 will some philanthropic and poetic neurologist come to our aid 

 with a revised metrical mnemonic?) 



The value of this functional analysis and its difficulty ap- 

 pear from a single illustration. Landacre has collected data from 

 various authors concerning the distribution of the gustatory 

 fibres in fourteen of the chief rami arising from the ganglion 

 mass of the fifth and seventh cranial nerves. In Petromyzon 

 only one of these rami carries gustatory fibres ; in Rana two ; 

 in Amblystoma. Triton, and Amia three ; in Pleuronectes, Gadus, 

 and Alenidia five ; while Ameiurus marks the extreme, with 

 gustatory fibres in twelve of the fourteen rami. Note that, in 

 the old neurology, these fourteen rami would be homologous 

 throughout the series : the new neurology shows their funda- 

 mental difference. 



But modern neurology is not content with this progress. 

 Each component must be traced in the one direction until its 

 peripheral distribution is mapped, and in the other to its com- 

 plex connections in cord and brain. As this is done, it appears 

 that each component, in whatever nerve or nerves distributed, 

 shows a uniform type of peripheral end organ, a fairly uniform 



