THE VITAMINES IN THE VEGETABLE KINGDOM 59 



pathogenic bacteria, like pneumococcus,!?. typhosus,B. coli communis, 

 certain intestinal streptococci and throat bacteria. The proof that 

 the vitamine was actually necessary was not available, acceleration 

 in growth only being demonstrated. Eberson (150) likewise found 

 that a yeast extract could increase the viability of a meningococcus 

 culture for more than a month. The medium consisted of agar, 

 peptone and potassium phosphate. The yeast was first extracted for 

 two hours at not more than 100C., and then sterilized for a half 

 hour at one atmosphere. 



Gonococcus. Cole and Lloyd (151) carried out vitamine experi- 

 ments on gonococcus. Tryptamine blood (tryptic digestion product 

 of casein) was used for cultivation. The gonococci cultures required 

 a suitable ion concentration, a considerable amount of free amino 

 acids and two kinds of vitamines to permit of favorable development. 

 One of these, easily adsorbable, is found in blood corpuscles and 

 possesses the ability to promote growth; the other occurs in tissues, 

 is relatively little adsorbable, and -has the peculiarity of bringing 

 about a secondary plentiful growth. The method of demonstration 

 of both vitamines is given in great detail. They are precipitated by 

 protein, but not in the presence of agar. Filtration through paper 

 removes the first vitamine completely and we have a good basis for 

 the idea that the substance from the blood corpuscles belongs to the 

 type of A-vitamine (antirachitic vitamine) which is found naturally 

 associated with fats; or it may also belong to a vitamine type that 

 is easily adsorbed by protein. On the other hand, the vitamine of the 

 tissues belongs perhaps to the B-vitamine type. Blood seems to 

 contain both substances although, in sheep serum, the first one 

 appears to be lacking. Morini (152) grew the gonococcus on gelatin 

 and beer yeast. 



The observations of Douglas, Fleming and Colebrook (153) suffice 

 to give us some idea of the conditions under which anaerobic bacteria 

 are best cultivated. Special measures for the exclusion of air are 

 shown not to be necessary, if the bacteria are given the opportunity 

 to provide themselves with local anaerobic conditions by the addition 

 of some porous material such as asbestos. It is very important, 

 however, to add to the bouillon culture, potatoes, carrots, cabbages, 

 and grapes, or better still, bran. An alcoholic extract of bran is 

 effective only when large amounts are used. 



