and Laboratory Methods. 



2163 



lM( 



A Simple Method for the Preparation of Auerbach's Plexus. 



The methods of preparation of Auerbach's plexus ordinarily recommended, 

 involving the use of osmic acid and other expensive agents, have made the 

 demonstration of this interesting structure unavailable to many workers. 



Auerbach's plexus has been easily and cheaply prepared in our laboratory 

 course in Histology by the following method, 

 which may be not without interest and value 

 to general workers. 



After the intestine has been macerated 

 (Stohr, '00, Histology, p. 272) the muscularis 

 can be easily peeled ofi in long strips, often 

 half an inch wide. The strips are now pinned 

 onto a cork or piece of wood in water. Fig. 1, 

 care being taken in drawing the tissue smooth 



not to stretch it at all. The mounting of the tissue on the cork has two ad- 

 vantages ; first, that it cannot wrinkle while being treated by the various re- 

 agents; second, that the minimum amount of fixing and staining re-agents is 

 used as the cork can simply be inverted in a suitable dish contaming the desired 

 fluids. 



After the tissue has been placed on the piece of wood or cork, it is ready to 

 be fixed. The ordinary re-agents may be used, but those containing osmic acid 

 seem to give the most satisfactory results. The best results in staining were 

 secured by the use of Heidenhain's haematoxylin and Brazilin, the first giving 

 the better differentiation. 



The following method was em- 

 ployed : 



Hermann's Fluid, 5 min. 

 Wash in running water 1 min. 

 Iron solution, 2 per cent., 15 



to 30 min. 

 Wash in running water 1 min. 

 Heidenhain's haematoxylin, 15 



min. to 1 hour. 

 Wash in running water 1 min. 

 Iron solution until excess of 

 stain is removed, 3-10 min. 

 The tissue is now removed from 

 the cork to a glass slide or a 

 watch glass, where the de-staining 

 may be watched. For this purpose 

 it is sufficient to place the slide over white paper, or on the microscope. When 

 the differentiation has been completed by this further use of the iron solution on 

 the tissue while it is on the slide, one can see the plexus without any mag- 



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r 



Fig. 2. 



