130 BULLETIN OF THE BUREAU OF FISHERIES. 



113, 115, and 118, representing very fat fish taken during early August, 191 1. The 

 commercial fishermen report that the very fattest specimens are obtained earlier in 

 the season. Fish no. 114 and especially no. 117 represent the opposite extreme, 

 i. e., the poorest fish for the August season. Undoubtedly no. 117 was at a stage in 

 which there was considerable diminution of fat below its maximum. This diminution 

 may have been due to any one of a number of factors, but one is led to suspect that the 

 fish has been long without food, even at this low station on the river. The marking 

 experiments of 1908 " give evidence that some at least of the August fish remain long 

 in the waters of the lower river. 



It is self-evident that where a fish has a low percentage of stored fat to begin with 

 there will be a less abundant erosion by the action of the lipases; therefore, other things 

 being constant, one can not expect in such an animal as high a percentage of concentra- 

 tion of the fatty products in the blood and tissue fluids as in fish that contain a greater 

 fat content. This factor a, the variation of the storage fat, has its influence on the 

 factor e, the number and size of the liposomes, as is indicated by the variations noted 

 in fishes nos. 120 and 125. 



SALMON LIPASES. 



The rapidity with which the stored fat of the salmon tissues is eroded when the 

 fasting begins will, of course, depend chiefly upon the second factor mentioned in the 

 section on the transference of fat in the pink muscle, namely, the amount or concen- 

 tration of the lipases. 



The phenomena of fat mobilizations in the body belong strictly within the group 

 of enzyme actions, for which the general law is so admirably stated by Wells: *" 



All tnetabolisra, then, may be considered as a continuous attempt at establishment of equi- 

 librium by enzymes, perpetuated by prevention of attainment of actual equilibrium through destruc- 

 tion of some of the participating substances by oxidation or other chemical processes, or by removal 

 from the cell or entrance into it of materials which overbalance one side of the equation. 



The presence of lipase in various animal tissues has been demonstrated often 

 enough. Hanriot '^ demonstrates the presence of lipase in the following fluids and 

 organs: Blood, lymph, urine; liver, pancreas, testes, spleen, thyroid. The lipase was 

 in greatest amount in the blood, liver, and pancreas. Kastle and Loevenhart ** showed 

 the presence of lipase in intestinal epithelium, which on account of its position as an 

 absorbing tissue is of more than passing interest. The evidence as regards the presence 

 of lipase in the blood plasma and in the lymph is somewhat contradictory, yet such 

 lipase is not only demonstrated, as given above, but its quantity has been shown to 

 vary under certain pathological conditions. Pathologists have followed the variations 

 in the quantity of lipase in necrosis * with fat formation. The pancreatic cells are 

 well-known lipase producers. It is to be expected, therefore, that there will be a 

 variation in the quantity of lipase that will reach the body fluids from this tissue. In 

 confirmation of this point lipase has been found in the urine of a clinical case of fatty 

 necrosis associated with inflammation of the pancreas.-'^ 



o Greene, C. W.: The migration of salmon in the Columbia River. Bulletin U. S. Bureau of Fisheries, vol. xxix, 1909. p. 131. 

 b Wells, H. G.; Chemical pathology, p. 68. Philadelphia, 1907. 

 c Hanriot: Comptes rendus de la Socicte de biologie, 1S96. p. 925. 

 rf Kastle and Loevenhart: American Chemical Journal, vol. xxiv. p. 49r, 1900. 

 f Flcxner: Journal Experimental Medicine, vol. 11, p. 194. 1904. 



/ Opic, Eugene L-: A case of hemorrhagic pancreatitis. The occurrence of a fat-splitting ferment in the urine. Johns 

 Hopkins Hospital Bulletin, vol. 13, p. 117. 1902. 



