208 THE AMERICAN MONTHLY [July, 



Microscopical Technique Applied To Histology. — IV. 



[from the FRENCH OF RENE BONEVAL.] 

 Continued from Vol. XIV, page 255, 



Fixed Cells. — To see the protoplasm, the lateral 

 wings, and the nuclei, extend a filiform tendon on a 

 piece of glass and fasten the two ends by paraffin. On 

 the middle of the tendon put a drop of picro-carmine, 

 and leave it for an hour in a moist chamber. [A saucer 

 with a layer of wet blotting paper and covered by a bell 

 glass makes a good moist chamber.] Wash and mount 

 in glycerine. Apply gentle presure with the needle. . . . 

 The anastomoses, which show the relations of the tendi- 

 nous cells, are not seen in this preparation. For these 

 remove the skin and place a portion of the tail in a large 

 quantity of an aqueous solution of picric acid. When 

 decalcified, harden by alcohol and gum. The sections, 

 freed from the acid by prolonged soaking in water, are 

 strongly colored by picro-carmine, and mounted in 

 formic acid glycerine (1 per cent solution,) which should 

 be allowed to penetrate the tissue very slowly. The 

 tendinous fibres are de-colored, the cells and their pro- 

 longations are stained red. . . . 



APONEUROTIC MEMBRANES. 



It is best to select a simple aponeurosis, that of a 

 frog's thigh being elegant and most effective. Ranvier's 

 method is the preferable one. Skin the frog and with 

 the scalpel circumscribe a portion of the aponeurosis 

 above the triceps muscle and take it off by the forceps. 

 Remove, by brushing, the endothelial cells of the sub- 

 cutaneous lymphatic sac and the pieces of muscle fibres 

 adherent to the under surface. Carefully spread on a 

 slide, partly dry it, stain with picro-carmine, wash till 

 the yellow color has disappeared, and cover by thin glass 

 supported on two sides by paraffin. Allow a drop of 



