YELLOW DISEASE OF HYACINTHS. 347 
On yellow turnips prepared in the same way, growth was very much greater than on 
potato. Such turnips contained much more sugar than the potato. Turnip and carrot 
cylinders were softened by the long continued growth of this organism (middle lamellz). 
Growth on nutrient starch-jelly is also very slow, even when hyacinth-starch is used. 
When diastase was added to the jelly, increased growth was apparent at once (see Smith, 
Bulletin 26, plate I, figs. 15-16), and at the end of 35 days this was estimated at 200 times 
the volume in the check-tubes. At the end of 62 days (water being well retained by the 
medium) there was a thin canary-yellow layer over the surface of the check-tubes (Stock 
310, for composition see Bact. phaseoli) equal to the growth given by the other tubes at 
the end of 5 days. The body of the starch in the check-tubes still preserved its bluish lustre, 
and on testing with Soxhlet’s solution for sugar more than nine hundred and ninety-nine 
one thousandths of the starch was found unchanged. The only copper reduction on boiling 
3 minutes was in an exceedingly thin film immediately under the bacterial layer. No brown 
pigment was formed on this substratum, with or without the diastase, and ‘the color of the 
slime was much brighter yellow than that in corresponding tubes of Bact. campestre or Bact. 
phaseoli. ‘There is always a 
strong iodine-starch-reaction, 
even in old cultures on starchy 
media, but some of the starch 
gives a red reaction (amylo- 
dextrin). 
Gelatin (fig. 144) and 
Loeffler’s blood serum are 
liquefied, but the change takes 
place slowly, does not occur 
in the absence of air, and is 
usually inhibited by the pres- 
ence of 5 or 10 per cent grape- 
sugar or cane-sugar. 
Dextrin stimulates growth; 
glycerin in small doses does not 
increase growth (?); in large 
doses it retards growth. In 
moderate doses grape-sugar, 
fruit-sugar, and cane-sugar Fig. 144.* 
stimulate growth. Lactose, 
maltose (?) and mannitol have no marked effect on growth. Bact. hyacinthi made a very 
feeble growth in a synthetic medium made as follows: Distilled water 400; sodium acetate 
2; dipotassium phosphate 0.8; magnesium sulphate 0.04; ammonium phosphate 0.04. The 
behavior was much the same as in Uschinsky’s fluid. 
This organism does not produce gas, and will not grow in the closed end of fermentation 
tubes in peptone-water, or peptonized beef-bouillon with grape-sugar, fruit-sugar, cane- 
sugar, milk-sugar, maltose (?), galactose, dextrin, glycerin, mannit, ethyl alcohol, methyl 
alcohol, or potassium nitrate. For some days there was no growth in the closed end of the 
tubes containing peptonized beef-bouillon and ordinary commercial maltose, but in the end 
there was a very feeble clouding in the closed end. Two repetitions of the experiment gave 
the same result, and no air-bubble appeared in the closed end of the tube on subsequently 
steamingit. In a third repetition made in 1906 using a very pure maltose there was no 
growth in the closed end (fig. 145). The organism is therefore, as far as known, a 
*Fic. 144.—Old stab-cultures of Bact. hyacinthi in gelatin containing 0.6, 0.8 and 0.9 per cent malic acid showing 
slow liquefaction confined to upper part of gelatin. Rims and precipitate bright yellow. 
