GRANULES AND FAT OF STRIATED MUSCLE 3 



I. .MATERIAL AND METHODS 



For the most part the material was obtained from the common 

 laboratory animals: frog, mouse, rat, rabbit, cat, dog, pigeon, 

 and from the bat. In a few cases the nutritive condition of the 

 animal was altered by special feeding in the laboratory. Human 

 material was used to a considerable extent and insect muscle 

 was also examined. 



The methods used in this study have a direct bearing on the 

 chemistry of the granules and fat droplets, and will be discussed 

 in some detail when considering that subject. The methods may 

 be briefly outlined as follows : 



1. Examination of fresh material. 



a. Preparations made without the addition of fluids. 



b. Preparations mounted in normal saline solution or 1 to 

 5 per cent solution of potassium hydroxide. 



2. Tests of solubility of interstitial granules and fat droplets 

 with alcohol, xylol, and with ether. 



3. Examination of preparations stained by various methods. 

 a. Simple alcoholic solutions of Scharlach R, and Sudan iii. 

 h. Herxheimer's Scharlach R. 



c. Nile blue sulphate and Nile blue chlorhydrate. 



d. Cresylviolett and Cresylechtviolett. 



e. The methods of Weigert, Altman, Benda, and Regaud. 



Herxheimer's ('01) stain is prepared by dissolving 2 grams of 

 Na OH in 100 cc. of 70 per cent alcohol, Scharlach R then being 

 added to saturation. The solution is filtered into a tightly clos- 

 ing vessel immediately before being used. Frozen sections or 

 teased preparations of fresh tissue, or material used after two 

 to twelve hours fixation in 20 per cent formalin, are washed in 

 60 per cent alcohol, transferred to the stain for three to fifteen 

 minutes, washed in 60 to 70 per cent alcohol twenty to thirty 

 seconds, followed by water, and mounted in levulose or glycerine. 

 If alcohol washing is omitted precipitates are formed. Fat drop- 

 lets are stained red, true interstitial granules and the protoplasm 

 of muscle fibers are not colored. Alum-hematoxylin or Cresyl- 

 echtviolett may be used as a counter-stain for the nuclei. 



