LABORATORY AND GREENHOUSE STUDIES. 



83 



Table XIV. — Growth of Bacillus coli and coconut No. 5 on agar containing neutral 

 red and various sugars, May 9-21, 1910, at 37° C. 



Culture and 

 medium. 



Bacillus coll: 



Without sugar. 



With lactose . . 



With dextrose. 



With saccha- 

 rose. 



With glycerin. . 



Coconut 5: 



Without sugar. 



With lactose. 



With dextrose. 

 With saccha- 

 rose. 



With glycerin. 



1 day. 



Pink growth; liquid 

 in V greenish flu- 

 orescent. 



Pink growth; slight 

 greenish color in V 



Same as without 

 sugar. 



.do. 



Pink growth; bright 

 green fluorescence 

 in V. 



.do. 



.do. 

 .do. 



.do. 



2 days. 



Excellent growth 

 in each tube. 



.do. 



.do. 

 .do. 



.do. 



Same as before, 

 only in each case 

 the green ex- 

 tends to bottom 

 of tubes. 



do 



.do. 

 .do. 



.do. 



7 days. 



Both growth and 

 agar entirely 

 changed toagreen- 

 ish-orange yellow. 



Growth on surface 

 bright pink. 



do 



Almost entirely 

 greenish yellow. 



Growth on surface, 

 pink; one-third of 

 agar greenish yel- 

 low. 



Changed from pink 

 to orange yellow 

 with a green tinge. 



Bright red; shows 

 no sign of greenish 

 yellow. 



....do 



Greenish yellow in 

 lower part of front. 



Bright red; shows 

 no sign of greenish 

 yellow. 



12 days. 



Orange color 

 throughout. 



No sign of change 

 of color to green- 

 ish; all red. 



All red. 



Greenish-orange 

 yellow through- 

 out. 



Pink growth; agar 

 greenish yellow, 

 fluorescent. 



Orange color 

 throughout. 



Bright red. 



Do. 



Most of growth is 

 pink; firm part 

 of agar greenish 

 yellow. 



No change in color. 



In these experiments coconut No. 1 reduced the color in nearly 

 every instance. The remainder were for the most part like Bacillus 

 coli and coconut No. 5. In nearly every case the culture in medium 

 without sugar changed to the greenish-fluorescent and then to an 

 orange-yellow color. In the media with lactose, dextrose, and gly- 

 cerin the same greenish-fluorescent reaction took place over a part 

 of the medium and growth, and then a darker purplish-red color 

 appeared. In the medium with saccharose there is the same appar- 

 ently permanent change to orange yellow from the pink to greenish 

 fluorescence as in the tubes with no sugar. 



macconkey's bile-salt agar with neutkal bed. 



The sodium taurocholate and the lactose in this medium are said 

 to have an inhibitive effect on nearly all but the intestinal bacteria. 

 The addition of neutral red further aids in separating the species. 

 The medium here used was made up according to the method in Eyre's 

 Bacteriological Technique, page 169.^ 



• See also Grunbaum, A. S., and Hume, E. H., " Note on Media for Distinguishing Bacillus Coli, Bacil- 

 us Typhosus, and Related Species, " in British Medical Journal, June 14, 1902, pp. 1473-1474. 

 228 



