356 CARL VOEGTLIX 



Recent work indicates that the growth of unicellular organisms, such 

 as yeast and certain bacteria, is dependent upon a supply of vitamin. 

 As a result of Bachmann's observations (1919), "Williams ()(&) (1919, 

 1920) has elaborated a promising method for the quantitative estimation 

 of the antineiiritic vitamin, based upon the observation that the growth of 

 yeast is proportional to the vitamin content of the medium. The relia- 

 bility of this method should, however, be fairly established before its 

 general adoption for work of this kind. 



Dnimmond(fe) (1917) has made observations on the influence of a de- 

 ficiency of fat-soluble or antineiiritic vitamin in the diet on the growth of 

 tumors. He comes to the conclusion that a lack of the fat-soluble vitamin 

 has no effect, whereas the absence of the antineuritic vitamin causes a 

 certain amount of inhibition. 



As a concluding remark it may be said that the work of this last decade 

 has resulted in numerous discoveries regarding the physiological and 

 pathological significance of vitamins. Although some facts have been 

 pretty firmly established, this does not hold for all observations made in 

 this field. As a matter of fact, the study of vitamins is still in its infancy 

 and sweeping generalizations, as so often made in scientific literature, do 

 not serve a good purpose. We are fairly well informed as to the distribu- 

 tion of the three vitamins in the more important foodstuffs. Further 

 progress will largely depend on the chemical isolation of these substances, a 

 phase which so far has attracted the attention of a relatively small number 

 of investigators. 



