The Interstitial Granules of Striated Mnscle etc. 315 



It seems certain that absolute alcohol dissolves the stainable 

 portion of the granules-presiimably the fatty portion. Whether the 

 other constituent of the granules (if there be such) has been dissolved 

 or is merely not visible cannot be determined. 



95 per cent alcohol is nearly as strong a solvent for the granules 

 as absolute alcohol. It requires somewhat longer for a complete ex- 

 traction. The solvent action of the weaker alcohols is very much less 

 than that of absolute alcohol. 70 per cent alcohol does not have much 

 effect on the strongly-refractive granules, but the faintly-refractive 

 granules usually disappear after one to seven days exposure. 



To determine the effect of the alcohols, two or three thin frozen 

 sections or very small teased specimens were put in several cubic centi- 

 meters of the alcohol. The volume of the solvent was more than one 

 hundred times that of the tissue. If a block of tissue be used the ex- 

 traction is much slower and seldom complete. Kölliker does not state 

 the strength of alcohol he used or the way the extraction was made. 

 Possibly some of the facts just given will explain his negative results. 



The large Q-granules of the wing muscles of insects are not dis- u 

 solved by absolute alcohol. If the sections be examined in water after 

 the alcohol treatment the granules are seen to be shrunken but none of 

 them have disappeared. These granules are also insoluble in ether. 



Ether dissolves all the liposomes, but its action is much slower 

 than that of absolute alcohol. Thin frozen sections or well-teased 

 specimens must be used, and the ether should be changed two or three 

 times. The ether penetrates very slowly. In teased fibers the peripheral 

 granules disappear first-usually in two or three hours. An expo- 

 sure of 24 hours or longer may be necessary to remove all the 

 I centra] granules. The extraction proceeds more rapidly if the specimens 

 be first rinsed in 70 per cent alcohol to remove the excess of water. The 

 fact that the peripheral granules dissappear first and the central ones 

 later indicates that the ether gradually penetrates the fiber and dis- 

 solves the granules, and that they are not removed by autolysis. In 

 many tissues the action of ether is much more rapid than the above 

 account indicates. 



Other solvents. Chloroform and acetone were used on a few spec- 



