NORMAL GROWTH CURVE FOR RATS 



4 5 



7 8 



10 11 12 13 14 15 16 17 18 19 20 21 22 

 Age in weeks 



GROWTH AS AN INDEX OF NUTRITION^ 



Deficiencies in food quickly influence the rate of growth in young animals, which we 

 therefore use for making experiments in nutrition. Rots are most sensitive to deficiencies 

 in diet during the first twelve weeks of life, when they grow most rapidly. The curve 

 shows the average week-by-week growth of large numbers of male(o-") and female {$) 

 rats kept on a suitable diet 



About a third of the Japanese soldiers were on the sick list every year, 

 suffering from this disease. Takaki, a naval surgeon, investigated the con- 

 ditions in the early eighties and decided that there was nothing wrong with 

 the climate or with the sanitary conditions. He suspected the diet. He sent 

 two warships on a long journey. One had the usual rations, in which white, 

 or "polished", rice was the chief ingredient. The other carried less rice, but 

 more barley, meat, vegetables and condensed milk. On the first ship about 

 two thirds of the men suffered from beriberi, and several died of it. On the 

 second ship only a few sailors became sick, and they were all sailors who 

 would not change to the newfangled diet. The Japanese government im- 

 mediately ordered the new diet for all its soldiers and sailors. The men's 



^Adapted from Teaching Nutrition to Boys and Girls by Mary S. Rose, The Macmillan 

 Company. After "The Influence of Food upon Longevity" by Sherman and Campbell, Pro- 

 ceedings of the National Academy of Science, Vol. 14. 



105 



