Abstract 



Fifty-one livers selected for pale color were found, on the 

 average, to wei^ 1,060 grams and to contain 2.k million "spec" units 

 of vitamin A per poxmd and 3.9 percent oil. "Bie vitamin A potency of 

 the liver oil ranged from 4,170 to 63^,000 units DjoOO x E (1 percent 

 1 cm, 3ii8 m ma, isopropanoljj per gram. The average potency of the 

 liver oil was 137,000 "spec" units per gram. It appears from tiie present 

 and from earlier work that paleness of liver is directly correlated with 

 hi^ vitamin A potency and with higti oil content. It is apparently not 

 associated with size of the seal or other readily ohservahle character- 

 istics. The data on vitamin A potency of the oil do not resemble a normal 

 distrihution. The data can he fitted "by the formula: f (X) = 23.k6 , 



4,150 + X 

 where X stands for the vitamin A potency of the oil and f (X) for the 

 numher of individuals having X as a potency. 



Introduction 



In 1946 the livers of eight Alaska fur seals (Callorhinos 

 ursinus ) were collected on the Prihilof Islands and analyzed for oil and 

 vitamin A in Seattle (Miyauchi and Sanford 1947). The vitamin A potency 

 was hi^ enovi^ in certain of the livers to warrant commercial exploita- 

 tion even in such a remote area as the Prihilof Islands. Consequently, 

 a search was made for a means of segregating the livers of high from tiaose 

 of low potency at the source. In 1947 it was found in a sample of 196 

 livers that the pale-colored ones were richer in vitamin A than the darker, 

 maroon-colored ones (Sanford, Kenyon, and Scheffer 1949) . In 1948, 51 

 pale-colored livers were sampled selectively. The results of the analyses 

 are given in this report. 



Collecting the Samples 



The fresh, warm livers from male fur seals approximately 3 to 4 

 years of age were collected. The carcasses of the seals had "been laid out 

 "by the sealing ^ng on the killing fields of St. Paul Island, Alaska, on 

 July 12 and 13, 1948. The livers of aibout 500 animals were examined, and 

 the 51 among than that appeared to he palest were selected for testing. 



The color of the fur seal liver ranges from maroon (as in heef 

 liver) to pale tan (as in cod liver) . By far the greatest numher of livers 

 axe shades of maroon. In selecting a sanple of the palest 10 percent the 

 color sense of the observer, rather than instruments, was relied upon. 



The 1948 sanples were handled in the same way as those collected 

 in 1947, Ihat is, each liver was washed in cold water, placed in a waxed- 

 ps5)er hag having a cellophane liner, and stored in a refrigerator at ap- 

 proximately 20° F. until they were analyzed in the fall of 1948. 



