550 ^'^6 Philippine Journal of Science mz 



broth, 2 of the 3 normal gave nearly normal offspring, while 

 1 gave a large proportion of coccoid forms. Of the 6 coccoid 

 cells, 1 gave a large proportion of coccoid, 2 gave a small pro- 

 portion of coccoid cells, and 3 nearly regular offspring. Trans- 

 ferred to ordinary agar and broth, all 9 gave cells with uniform, 

 normal morphology. Sown on maltose-litmus agar, all 3 cultures 

 of normal-cell ancestry gave acid types, and of the coccoid 

 strains 2 gave acid and 5 alkaline cultures. 



From a secondary colony of three days' growth similar to 

 the above, cells were spread over the surface of maltose-litmus 

 agar in Petri dishes. Forty distinctly blue and 6 bright red 

 colonies were obtained. 



From the above and similar experiments, it was proved that 

 the secondary colonies contain a mixture of acid- and alkaline- 

 forming cells and that there is no constant correlation between 

 the morphology or degree of involution of cells and their fer- 

 mentative properties. Further, it was shown conclusively that 

 the first few generations from an involution cell may show a 

 large proportion (in some cases nearly one-half) of involution 

 cells. Later, the morphology of the cells becomes normal or 

 nearly so. 



In an ordinary transfer from a secondary colony to fresh 

 maltose-agar one usually obtains an acid-forming growth, al- 

 though in some cases not so well marked as when a "pure" 

 acid strain is sown- It is probable that in this mixture, taken 

 from a secondary colony, the acid formers usually outgrow the 

 others, so as to give a more distinct red to the maltose-litmus 

 agar. 



With regard to agglutination, the parent stock and the red and 

 blue races isolated from it gave practically the same results. 

 A serum obtained by inoculating a rabbit with a pure culture 

 of the stock gave agglutination to Ysoo in all three strains. 



II. VARIATION IN MORPHOLOGY 



In another culture of dysentery. No. 42 of the Shiga-Kruse 

 type, a variation of a different kind was studied. This culture 

 was kindly furnished me by Dr. C. S. Butler of the United States 

 Navy, August 19, 1912, and came from a stool of a case of 

 dysentery. A pure culture was obtained by isolating a single 

 cell, August 30, 1912. Descendants from this normal cell grown 

 in hanging drops showed, for the most part, only normal cells. 

 From this pure culture a single cell was again isolated and grown 



