76 THE VITAMINES 



which are not always considered as deficiency diseases, though they 

 might turn out to be such. Because of insufficient irrigation of the 

 fields and periodic dry spells, we see domestic animals, feeding on 

 wretched vegetation for months at a time, dying from diseases which 

 we shall describe more in detail further along in the chapter. Here, 

 we are perhaps dealing with conditions which follow each other 

 like the individual links of a chain. As a result of the unfavorable 

 condition of the soil and the paucity of soil bacteria, the vegetation 

 suffers. The animals which must feed on this vegetation either 

 become sick, or else are not in perfect health, though no unusual 

 symptoms may be apparent. Subsequently, their offspring and 

 the children drinking the milk of such animals are naturally poorly 

 nourished; the same is true of grown people who use the meat of 

 such animals. Indeed, these conditions could as well prevail in 

 European countries where, because of the war, the number of cattle 

 has decreased, leading to the exhaustion of natural fertilizer, which 

 could not be replaced by artificial fertilizer because of the difficulty 

 of obtaining it. The diagram, illustrative of the relationship be- 

 tween the above mentioned factors, is shown below. 



^Unfavorable soil conditions 

 Lack of soil bacteria Insufficient fertilizer 



I T 



Wretched vegetation > Diseased animals 



I 



Meat and milk of incomplete 

 nutritive value. 

 Avitaminoses in man 



LIFE WITHOUT BACTEEIA 



As we have stated several times previously, the incomplete knowl- 

 edge of the role of the bacterial flora in animals is the cause of a 

 great gap in the conception of the general significance of the 

 vitamines. We know, or at least we suppose, that some bacteria 

 are independent in their metabolism of an outside addition of vita- 

 mine, and since we know that a great number of bacteria live in the 

 intestinal canal, either in symbiosis or else as a parasite, we can 

 easily imagine that their functions may have something to do with 

 supplying the host with vitamines. 



