916 



SCIENCE 



[N. S. Vol. XXVII. No. 702 



iculate. The fibers entering the mucosa 

 are certainly not lateralis, as no canal or 

 pit organs are there found; the fibers are 

 also smaller than are the lateralis fibers. 

 They may, therefore, be either general cu- 

 taneous or visceral sensory, with the pre- 

 ponderance of evidence in favor of the 

 former, partly on the ground that the 

 meduUated innervation in mammals and 

 birds, the other forms in which such fibers 

 a,re known, is trigeminal and partly because 

 the weight of evidence in the teleosts is 

 against the supposition that visceral sen- 

 sory fibers are present in this region. 

 Young cod and gold fish were studied with 

 reference to the presence of medullated 

 fibers in the mucosa, but none could be 

 demonstrated. 



The Ischio-coccygeal Plexus as a Pathway 

 for Cutaneous Innervation in the Leop- 

 ard Frog: Elizabeth Hopkins Dunn, 

 The University of Chicago. 

 Gaupp in the 1896 edition of Ecker's 

 und Wiedersheim's "Anatomic des Pro- 

 sehes" makes no mention of a cutaneous 

 innervation by way of the ischio-coccygeal 

 plexus, branches from which are there 

 traced to the pelvic viscera and the pos- 

 terior lymph heart. 



In dissection of the ischio-coccygeal 

 plexus of Bana pipiens the nervus coc- 

 cygeus was found to send several terminal 

 branches to a limited area of the skin about 

 the cloaCal opening. 



At the point in the nerve at which the 

 last visceral branch is given off a study of 

 the relations of the individual fibers was 

 undertaken. The last visceral branch con- 

 tains from fifteen to twenty medullated 

 fibers, the cutaneous portion about forty 

 medullated fibers. 



The small number of medullated fibers 

 at this point makes possible the isolation 

 of the individual fibers by teasing in gly- 



cerin. One per cent, osmic acid was used 

 as a fixing and staining reagent. 



A careful study of material, including 

 the trunk of the nerve above the point of 

 branching and the visceral and cutaneous 

 branches in their continuity with the main 

 trunk, revealed in three consecutive prepa- 

 rations the division of at least one medul- 

 lated fiber in each preparation occurring in 

 the trunk just above the point of separa- 

 tion of the branches. Of these dividing 

 fibers one limb passed toward the viscera 

 while the other continued with the cutane- 

 ous portion of the nerve. 



The weight of evidence seems to be in 

 favor of the afferent character of these 

 fibers. 



If this be true, unless an independent 

 functional value can be established for the 

 individual neuro-fibrillfe in the neuraxis, it 

 would appear that we have in such a dis- 

 tribution of the ramifications of a single 

 nerve fiber an anatomical explanation for 

 the close connection between visceral and 

 cutaneous areas which has been suggested 

 by the findings on the pathological side 

 shown by Head's classic work on disturb- 

 ance of sensation with reference to visceral 

 disease. 



A close physiological connection between 

 the pelvic viscera and the adjacent regions 

 may also be accomplished by means of such 

 dividing fibers. 



Degeneration in the Ganglion Cells of Cam- 

 harus hartonii Gir: Hanspoed Mac- 

 CuEDT, Alma College. 

 Within the last decade a large number 

 of experiments have been performed on 

 vertebrated animals to ascertain to what 

 extent the nerve roots, ganglia and gan- 

 glion cells are affected when a nerve trunk 

 has been severed. The results have varied 

 greatly, but in by far the greater number 

 of these experiments, distinct alterations in 

 the size and structure of the parts affected 



