92 DARMON A. RHINEHART 



each follicle, the former lying some distance from the bases of the 

 cells, the latter directly on the cells. Small curved branches 

 from the secondary plexuses end in knobs and look as if they pen- 

 etrate between the cells while others are straight indicat ng that 

 their endings lie on the basal ends of the cells. 



Crissafulli's ('92) description of these nerves agrees in almost 

 all particulars with that of Anderson, with the exception that he 

 found ganglion cells here and there throughout the g and. 



TECHNIQUE 



The only technical methods for staining nerve fibers that were 

 found of value in this work were the intra-vitam methylene blue 

 method of Ehrlich and the Golgi method. 



The methylene blue method was carefully tried in all its forms, 

 but was only valuable in staining the larger nerves accompanying 

 the blood vessels into the gland. 



The original Golgi method in the rapid and mixed form to- 

 gether with the modification of Berkeley gave poor 2'esults. The 

 most successful and complete staining of the nerves was secured 

 by the use of the 'double impregnation' method of Cajal, modified 

 as to the length of time the tissues were allowed to remain in the 

 different fluids. 



This method consists in fixing small pieces of tissue for from six 

 to eight days in a mixture made up of four parts of a 3.5 per cent 

 solution of potassium bichromate and one part of a 1 per cent 

 solution of osmic acid. After fixation and a careful washing in 

 distilled water the tissues are put into a 1 per cent solution of 

 silver nitrate for three days. This is followed by a second fixa- 

 tion for an additional three days, and a second impregnation 

 with silver. After the first day in the second silver solution free 

 hand sections are examined at intervals until the nerves are found 

 to be satisfactorily stained. The tissues are then rapidly dehy- 

 drated in several changes of 95 per cent and absolute alcohol, and 

 are quickly imbedded in celloidin, the blocks being hardened in 

 chloroform. Sections, 25 to 100 microns thick, are cut under oil, 

 cleared on the slides in carbol-xylol and xylol, and mounted 



