6 H. HAYS BULLARD 



Bell ('10, '11) adopted Albrecht's term 'liposome.' As desig- 

 nated by him, none of the liposomes stain with acid fuchsin but 

 all of them may be colored with Herxheimer's Scharlach R and 

 all are soluble in alcohol. He describes certain of his liposomes as 

 faintly-refractive and is evidently of the opinion that they corre- 

 spond to the faintly-refractive interstitial granules of Knoll, 

 Kolliker and other observers. 



I find that the faintly-refractive granules described by Knoll 

 ('80, '91) in the heart and skeletal muscles of the pigeon are 

 readily stained by the acid fuchsin method but do not stain by 

 Herxheimer's method. These granules would thus come within 

 the category of liposomes as the term is used by Albrecht, but 

 they form no part of the liposomes of Bell. The faintly-refract- 

 ive liposomes of the latter author are faintly-refractive fat drop- 

 lets and do not correspond to the faintly-refractive granules of 

 Knoll. Knoll himself pointed out that his faintly-refractive 

 granules correspond to the true interstitial granules of Kolliker. 



The term true interstitial granules will be used in this paper 

 to correspond to the true interstitial granules of Kolliker which 

 as previously mentioned include a part of the bodies described by 

 Altmann, Benda, and Arnold respectively, as bioblasts, mito- 

 chondria and plasmasomes. 



The term 'fat' is here used to include lipoids and cholesterin 

 compounds as well as the fatty acids and their glycerin esters. 



III. RELATION OF INTERSTITIAL GRANULES AND FAT DROPLETS 

 TO COLOR AND STRUCTURE OF :\IUSCLE 



a. Light and dark muscle fibers 



KJrause ('64) found that the fibers of the red muscles of the 

 rabbit contain more interstitial granules than are present in the 

 fibers of white or pale muscles. Griitzner ('84) described two 

 types of fibers in human muscles, cloudy or dark and pale or white. 

 He found that all human muscles contain both types of fibers and 

 believed that dark fibers give macroscopically the red appearance 

 to muscles while light fibers correspond to white or pale muscles. 



