XXVIl, 2. Wilson : Improved methods of utilising organised structures. 229 



vais between the holes for the dowel-pins. The calibre of the pins 

 may be 1 mm, or less, and the distance between them must be 

 exactly the same at either end , say 2 or 3 mm. The individual 

 pins, which correspond to one another at each end of the chamber, 

 must not only be equidistant from their neighbours , but also from 

 the edge of the embedding-chamber as defined by the lateral margin 

 of each end-plate. 



In order to carry out the nerve-strand method of embedding 

 with these appliances it is only necessary to take a nerve filament, 

 prepared either according to my former description (1;, or as more 

 recently recommended by Neumayer (2). This filament is to be 



2. 



Fig. 2. Showing embedding chamber set up with all parts in position 

 except one of the side-blocks. 



(Lettering as in fig. 1.) 



gently stretched around the two pairs of pins projecting up from 

 the base-plate so that two perfectly parallel strands traverse the 

 surface of the base-plate on the site of the embedding chamber. 

 (By appropriately utilising the thickness of the pins, four strands 

 instead of only two parallel with one another may be obtained if 

 desired.) Only sutficient tension should be used to keep the filament 

 taut without undue stretching of the nerve -tissue. The loose ends 

 should be crossed on the plate at one end, and held there in posi- 

 tion whilst the corresponding end-plate is placed in position and its 

 dowel-pins firmly pressed home, thus clamping the nerve filament 

 securely in position. The second end-plate may then be placed in 

 position in like manner. When this has been accomplished the two 

 parallel nerve filaments will be in actual contact with the surface of the 



