292 KAN-ICHIRO MORISHIMA 



yellow granules appear on the surface. Their borders can be 

 distinctly seen by means of a hand lens or a low power micro- 

 scope. Day by day they increase in thickness, in size, and in 

 number, as the mother colonies enlarge. Later a confluent 

 growth of the daughter colonies may entirely overgrow the 

 mother colonies. 



B. On sugar plates containing indicators 



On plates which contain decolorized china blue the daughter 

 colonies appear, blue in color and inside the mother colony. 

 After a few days they increase in size, color, and number. The 

 blue color doubtless is due to the production of acid by daughter 

 colonies. Ten days or two weeks later, owing to a reduction of 

 the dye, some of the fully grown colonies may have a brownish 

 yellow color. The number of large blue daughter colonies that 

 develop on the plate varies greatly according to the strains of 

 typhoid bacilli employed, there being in some cases only 1 or 

 2, and in other cases 50 or 100 colonies. 



Agglutination tests made with cultures of daughter colonies 

 also showed no differences from those done with the original 

 strain. When we used methylene blue eosin xylose plates 

 (Holt-Harris and Teague, 1916) the mother colonies showed 

 a pinkish color, but the daughter colonies appeared as white 

 dots by transmitted light, some of which soon became black. 

 These colonies exhibited the same rapidity of growth in the 

 succeeding days that was described in the case of the blue daugh- 

 ter colonies on the china blue plates. 



When we fished daughter colonies from the above plates and 

 inoculated into the corresponding sugar broth, the latter showed 

 acid production in twenty-four hours. We plated ten typhoid 

 strains on eleven different 1 per cent sugar plates. On arabinose, 

 dulcitol, raffinose, xylose and rhamnose plates from twenty to 

 fifty strains were planted. The cultures were observed for about 

 three weeks. 



Below are described the variations in growth exhibited on 

 each sugar medium: 



