STORAGE OF FAT IN MUSCULAR TISSUE OF KING SALMON. 109 



female. The protocol for no. 127 is the male. By reference to the protocol it will be 

 seen that the trunk pink muscle contains a medium amount of intermuscular fat. The 

 fat droplets have a distribution that is normal, but the relative size of the droplets is 

 small so that the amount of fat represented is evidently greatly decreased as compared 

 with the standards from Ilwaco. 



The intramuscular fat of the trunk pink muscle was present in much lower amount 

 than in the fatter specimens from Warrendale but also in greater amount than in the 

 poorer specimens. The characteristic of these CeHlo fish in this regard is in the 

 relatively lo\v fat in the larger pink muscle fibers. Only scattered traces of intramuscular 

 fat were found in any of these fibers, and those traces usually in the neighborhood of 

 intermuscular fat. 



Keeping in mind the condition of the dark muscle from the salmon from Warrendale 

 it was to be expected that the corresponding tissue in the Celilo salmon would have a 

 considerable loading of fat. This w-as found to be the case. The specimens from the 

 Cement Wheel agreed in that the dark muscle fat was definitely diminished in quantity 

 in comparison with average fish from Warrendale, and sharply diminished in comparison 

 with Ilwaco specimens. The samples chosen were the average of the type running at 

 that time, August 22 and 23. The grade of fish at this season is very much lower than 

 at an earlier date, but this is a factor which characterizes the entire series studied and 

 does not interfere with the comparison. 



The caudal pink muscle was practically free of fat in each of the specimens studied. 

 The caudal dark muscle had both intermuscular and intramuscular fat, but in each 

 instance about 40 to 50 per cent as much as in the trunk muscle of the same specimen. 

 The female of the Cement Wheel specimens showed less fat in both the trunk and caudal 

 dark muscle than was present in the muscles of the male, notwithstanding the fact that 

 the male gave other evidences of a greater retrogression in general than did the female. 



Little or no variation could be shown between the salmon taken at the Tumwater 

 seining grounds and those taken at the Cement Wheel. In each instance there was a 

 fair showing of intermuscular fat in the pink muscle, and an amount of fat within the 

 fibers of both the pink and dark muscle which characterize an approximately average 

 grade running below the Cascades. 



At the time of this visit no fish were running which were judged to be of as high a 

 grade as no. 120 and no. 122, described in the protocols from Warrendale. 



PROTOCOL. 



Male salmon (no. 127), length 800 mm., taken at Seuferl's Cement Wheel, The Dalles of the Columbia, 



August 22, igii. 



The fish was silvery in color, with dark dorsal surface; shape that of a half -exhausted specimen; 

 flesh oily in appearance and to the touch; visceral mass small and degenerated. 



Microscopic examination of the trunk pink muscle, I . — The intermuscular fat is medium in quantity. 

 There are a few large droplets, the largest 40 n in diameter, but many smaller droplets, especially of 

 the size from 3 to 6 /( in diameter. The amoxint of fat is much less than in the specimens like no. 118 

 from Ilwaco, estimated at 40 per cent. The distribution of the intermuscular fat varies in different 

 parts of the preparation. In certain parts the amount is not more than 25 per cent that described above. 



The intracellular fat varies extremely in the different fibers. In the small fibers, size 40 to 70 /i in 



diameter, the fat droplets are fairly numerous but of larger size and greater number around tlie surface 



of the fiber. These fibers (1/12 oil immersion) show that the fat droplets aggregated around the surface 



are within the sarcolemma and superficial. In the center of the fibers the liposomes are much smaller, 



19371°— vol 33—15 S 



