INNERVATION OF INTEGUMENT OF CHIROPTERA 309 



The first investigator, however, to make an intensive study 

 of the arrangement of the nerves in the flying membranes was 

 Schobl ('71), who states that the nerves of the patagimn are 

 naturally divided into five layers. The first layer, situated in 

 the innermost stratum of the flying membrane, contains the 

 larger nerve trunks, the main blood vessels, the chief muscles 

 and the elastic bands. The second nerve layer is double, one 

 part lying above, and its duplicature below the first layer. The 

 nerve trunks of this layer branch dichotomously again and 

 again, forming an irregular network. The third layer of nerves, 

 which is also double, lies external to the previous one, on a level 

 with the finest blood vessels. As to the size of the nerve trunks 

 of this layer, Schobl states that they consist usually of two, very 

 rarely of four, non-meduUated fibers. The fourth nerve layer, 

 likewise double, lies outside of the third. It consists through- 

 out of an irregular net of single non-meduUated fibers. The 

 meshwork in this layer, however, arises not by an interlacing 

 of fibers, as is the case in the other two layers, but by direct 

 anastomosis of single non-medullated fibers. On certain fibers 

 of this layer Schobl noted a number of enlargements or swellings 

 ('Krootenpunkten'), which were triangular, square, or poly- 

 hedral in form, having a fine granular appearance, but exhibit- 

 ing no nuclei. He also occasionally saw more or less similar 

 spindle-shaped enlargements in the course of a single fiber, 

 especially the larger ones. The fifth and last nerve layer, also 

 double, Hes immediately over the previous one on the surface 

 of the cutis, ordinarily remaining attached to the deepest cells 

 of the Malpighian stratum. The fibers of this layer are likewise 

 non-medullated, and have a diameter ranging from O.Q/x to 

 immeasurable fineness. This layer arises from the previous 

 one by the division of the finest fibers of the latter. At the places 

 of division of the fibers, the swellings which were found so fre- 

 quently in the last nerve layer seldom occur in this one, and the 

 spindle-shaped variety is lacking entirely. This layer of ex- 

 tremely fine non-medullated nerve fibrils lying immediately at 

 the surface of the corium, partly between the lowest cells of the 

 Malpighian stratum, Schohl holds as a terminal. He further 



