The Interstitial Granules of Striated Muscle etc. 331 



muscle were examined Aug. 29 and Sept 7, but no decided increase 

 in the liposomes could be seen. 



A leopard frog similarly fed on palmitic acid from Aug. 28 th to 

 Sept. 7 Shows no decided changes in the liposomes. 



Aug. 22. Leopard frog, weight 42.5 g. Plug shows only faint lipo- 

 somes present. Fed sodium oleate. Killed Sept. 7. No decided change 

 in the liposomes. 



The frogs fed on oleic acid all died before any definite results were 

 obtained. It would have been very instructive to get the effects of 

 feeding tripalmatin, tristearin, lecithin and tributyrin, but these sub- 

 stances were not available. 



It is apparent that if the frog be fed an excessive amount of fat, 

 the fat will be rapidly stored up in the muscle fibers. The liposomes 

 rapidly become more refractive and stain more intensely. Even when 

 no liposomes at all are present, the fibers fill up with them after a few 

 days of feeding. When the liposomes first appear, they are very small 

 and faintly-refractive. They never stain with osmic acid at this stage, 

 but they may be shown with Herxheimer's solution. After the second 

 day of feeding they may stain a light brown with osmic acid — the 

 intensity of the osmic stain increases as the liposomes become larger and 

 more refractive. 



Only olive oil and fat meat produced the increase in the liposomes. 

 Negative results were obtained with palmitic acid, sodium oleate, 

 Starch, grape sugar, and lean meat. The inference is that olein is the 

 substance taken up by the liposomes. The early staining of the lipo- 

 somes with osmic acid also supports this view. 



The rat (Mus decumanus). It was found that when a rat has lost 

 as much as 20 per cent of its body weight only a few faint liposomes 

 are left — often none at all are to be seen. When it has lost 25 per cent 

 or more there are seldom any liposomes at all to be seen. The experi- 

 ment was made of starving the rat until the liposomes were removed, and 

 then feeding again to see how they are regenerated. 



I am indebted to my Assistant, Mr. T. J. Heldt, for devising a glass tube and 

 plunger by which these or any other solid substance can be readily put into the 

 frog's stomach. 



