92 CHRISTIANNA SMITH 
From this brief summary of the significance of lipoids in the 
cells, the evidence seems very strong that besides producing the 
peculiar semifluid, semisolid state of protoplasm, that the lipoids 
are in some way intimately connected with the metabolic 
processes. 
SUMMARY 
1. Lipoids are characteristically present in normal kidney 
cells either masked or free and are shown after a dichromate 
fixation with the application of heat. 
2. In certain species (example, cat) different portions of the 
tubule have characteristic lipoid formations which may indicate 
a difference in function. 
3. The mitochondrial rods of the ascending limb of the medul- 
lary loop are by nature strongly lipoid and are resolved into 
lipoid granules under certain conditions. 
_ 4, Lipoid droplets containing a large percentage of olein are 
not preserved by Bell’s method. 
5. The presence, distribution, and in some cases, characteristic 
distribution of lipoids in kidney cells suggest that they may be 
intimately connected with metabolic processes besides the 
possible function attributed to them by some of influencing the 
physical state of the protoplasm. 
BIBLIOGRAPHY 
Bez, E. T. 1909 On the occurrence of fat in the epithelium cartilage, and 
muscle fibers of the ox. Am. Jour. Anat., vol. 9, pp. 401-412. 
1910 The staining of fats in epithelium and muscle fibers. Anat. Rec., 
vol.:4, pp. 199-212. 
1911 Interstitial granules of striated muscle. Internationale Monat- 
schrift fiir Anatomie u. Physiologie, Bd. 28, 8. 297-347. 
1912 The interstitial granules (liposomes) in fatty metamorphoses of 
striated muscle. Journal of Path. and Bact., vol. 17, pp. 147-159. 
1914 On the differential staining of fats. Journal of Pathology and 
Bacteriology, vol. 19, pp. 105-113. 
Butuarp, H. H. 1912 On the interstitial granules and fat droplets of striated 
muscle. Am. Journ. Anat., vol. 14, pp. 1-46. 
1916 Fat and mitochondria in cardiac muscle. Am. Jour. Anat., 
vol. 19, pp. 1-32. 
