FISHERY INDUSTRIES OF THE UNITED STATES, 1939 231 
grown satisfactorily to an age of at least 7 weeks on the diets which 
contained 30 to 35 percent of this experimental meal. In fact, the 
protein of this meai was found to have a high nutritive value and under 
some conditions the exposure of meals to high humidity and heat 
markedly increased the vitamin K content and some vitamins of the 
B complex through bacterial action. 
The data also showed that any subnormal growth in chicks fed diets 
incorporating the experimental meals was due to a deficiency state 
rather than any toxicosis caused by some protein or fat decomposition 
product. This finding is very important in actual practice, since it 
means that fish meals may be freely incorporated in the rations of 
farm animals for their valuable protein and mineral content, provided 
reasonable care is taken to balance the rations for all other food ele- 
ments by a proper selection of cereals and leafy legumes, 
The results obtained in this study have been prepared for publication 
under the title “Studies on the Feeding Value of Fish Meals: Effect of 
Heat and Moisture on Protein.” It is planned to continue these 
studies to obtain further data relative to the development of vitamin 
K and the vitamin B complex in the experimental meals. 
FLUORINE IN FISHERY PRODUCTS 
These studies were completed and the results as outlined in last 
vear’s annual report were published as Fishery Investigational Report 
No. 44, “Study of the Metabolism of Natur ally Occurring Fluorine in 
Canned Salmon and Mackerel.” The conclusions derived from the 
study were: (1) Inorganic fluorine is three times as effective in pro- 
ducing defects of tooth enamel as is naturally occurring fluorine from 
canned salmon and mackerel; and (2) all of the fluorine ingested from 
the basal diet, and 67 percent of the added inorganic fluorine is stored 
in the body of the rat. Only 21 percent of the fluorine from the canned 
salmon or mackerel is stored, indicating that the naturally occurring 
fluorine from these fish is stored at only about one-third of the rate of 
added inorganic fluorides. Under practical conditions no toxicity 
symptoms need be expected from the ingestion of naturally occurring 
fluorine of fish, as evidenced from these tests. 
RESEARCH ASSOCIATES AND STUDENT ASSISTANTS 
Because of the relatively small size of the Bureau’s technological 
staff, and the rather broad field of research it must cover, it is only 
possible, as indicated previously, to undertake those problems which 
are of a fundamental nature, those which have promise of the greatest 
value to the largest number of persons whose livelihood depends in 
whole or in part on the fisheries, and those which are possible with the 
funds and personnel available. For this reason the Division cannot, 
with present facilities, attack problems of special or restricted interest 
affecting certain products, process, methods, or industries. However, 
the Bureau has available, under an arrangement similar to that of 
other scientific Government bureaus, facilities for research associates 
and student assistants in its laboratories. The salaries and expenses 
of these employees are paid by the firms or groups who are interested 
in the problems on which they are working, and the investigations are 
carried out under the supervision of the Bureau’s technologists in its 
246406—41——_4 
