The Interstitial Granules of Striated Muscle and their 

 Relation to Nutrition. 



By 



E. T. Bell, 



From the Anatomical Laboratory^), University of Missouri. 



(With Plate XVI.) 



The term "interstitial graiuile" was introduced TbyKölliker in 1857, 

 and was applied by him to the granules in striated muscle between the 

 fibrillae. Kölliker distinguished "true" interstitial granules from fat 

 droplets, but stated that the fat droplets were probably metamor- 

 phosed granules. Various views as to the origin, chemistry, and signifi- 

 cance of the granules are to be found in the literature. A majority of 

 observers seem to believe that they represent some form of reserve food 

 substance ; but others regard them as products of destructive metab- 

 olism. They have been described in some instances as purely albumi- 

 nous, in others as purely fatty. It is probable that some interstitial 

 granules are artefacts produced by the fixatives employed. Some of 

 the confusion in regard to the granules is due to the fact that certain 

 granules of insect muscle are widely different chemically from those 

 occurring in vertebrate muscle. 



Among the unsettled questions in connection with this problem 

 are: What is the chemical composition of the granules? Does their 

 composition vary in different species, or in the individuals of the same 

 species? Does their number, size, or composition depend upon the nu- 



') The Department of Anatomy is cooperating with the Agricultural Experi- 

 ment Station in a study of the process of fattening. This is the third of a. series 

 of papers. 



