Hara, Sheaths of the Peripheral Nerves. 155 
(2) The neurokeratin sheath has a large number of pores 
or meshes and presents a net-like appearance. The size and 
‘shape of the meshes are, however, highly variable. 
(3) Neither the outer nor inner layers of the neurokeratin 
are interrupted at the node of RANvirrR, but become continuous 
through it with the corresponding layers of the adjoining inter- 
nodes. 
(4) The present observations do not agree with Wynn's, 
but confirm the previous statements of EwaLp and KUHNE. 
(5) The present technique brings out a more detailed 
structure of the neurokeratin than has been obtained by other 
investigators. 
BIBLIOGRAPHY. 
EWALD and KUHNE: Ueber einen neuen Bestandtheil des Nervensystem. 
Verhand. d. naturh. med. Vereins zu Heidelberg. Vol. 1, Heft 5, 1876. 
CHEVALIER, JOSEPHINE: Chemische Untersuchung der Nervensubstanz. 
Zettsch. f. Physiol. Chem., Bd. X, 1884. ; 
KUHANE and CHITTENDEN: On Neurokeratin. Zhe Mew York Medtcal 
Journal, Feb. 22 and March 1, also in Zezt. f. Bzol., Bd. 26, 1890. 
KOLLIKER: Handbuch der Gewebelehre. Bad. II, 1896. 
WLASSAK: Herkunftder Myelin. Arch. 7. Entwicklungsmechanthk der Or- 
ganismen. Vol. VI, Heft IV, 1808. 
Wywn, W. H.: The minute structure of the medullary sheath of nerve- 
fibers. Journ. Anat. Phystol., Vol. 34, 1900. 
KAPLAN, L.: Nervenfairbungen (Neurokeratin, Markscheide, Axencylin- 
der). Arch. f. Psych. u. Nervenhetdlkunde, Bd. 35, Heft 3, 1900. 
The above bibliography is supplementary to the references given by K6L- 
LIKER, WYNN and KAPLAN. 
