The Interstitial Graimles of Striated Musole etc. 329 



During the summer months, therefore, the Hposomes fade out. In 

 a fresh preparation faintly-refractive granules are visible in the dark 

 fibers; but those in the light fibers can't be seen without a stain (fig. 2). 

 Here also, as in the emaciated cat and rat, the osmic-staining portion 

 of the liposome has been removed; but the remaining part can be 

 stained with Herxheimer's solution. 



During the early autumn the liposomes gradually regain their 

 staining power. The staining-intensity with Herxheimer's solution 

 increases. The power to reduce osmic acid reappears and gradually 

 increases. 



The peculiar cycle of changes in the liposomes is presumably due 

 to the feeding habits of the frog. The following explanation is offered. 

 During the winter the frog hibernates. Fat is continually being formed 

 in the muscle fibers, perhaps partly from the muscle substance. This 

 fat is being used all the time to carry the animal thru the hibernating 

 period. In the summer however when the frog begins to feed again, the 

 formation of fat in the muscle ceases and the supply on hand is grad- 

 ually used up. 



e) Effect of special feeding on the liposomes. 1. The frog. Some inte- 

 resting results were obtained by feeding summer frogs on special rations. 

 It has been pointed out above that in the summer months (June, July, 

 and August) the muscle fibers contain very little fat. In a great many 

 animals, in July and early August at least, no liposomes at all can be 

 demonstrated in the hght fibers, and those in the dark fibers are very 

 small and faint and can only be stained with Herxheimer's solution. 

 Some young frogs were found in which no liposomes at all could be 

 shown. It was found that when frogs in this condition were fed heavily 

 on olive oil or fat meat for a few days the fibers become loaded with 

 liposomes, giving a picture similar to that found in winter animals. 



To determine the condition of the muscle at the beginning of the 

 experiment, a small piece of muscle from one gastrocnemius was 

 removed and studied. Some typical experiments will be given. 



Leopard frog (Rana pipiens). No. 4. July 20, 1910. Weight, 

 24.4 g. Plug from rt. gastroc. shows large number of granules in both 

 dark, and light fibers, but all are very faint. Fed heavily on olive oil 



