YELLOW DISEASE OK 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 lamellae). 



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 vSniith, 

 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 Ijeing well retained by the 

 medium) there was a thin canary-yellow layer over the surface of the check-tubes (Stock 

 310, for composition see Bad. 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 vSoxhlet's solution for sugar more than nine hundred and ninety-nine 

 one thousandths of the starch was found unchanged. The only copper reduction on jboiling 

 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 liacl. cum pcslrc or Had. 

 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 ( M ; 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 eft'ect on growth. Bad. Iiyacintlii made a very 

 feeble o-rowth 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 vcrv 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 

 steaming it. In a third repetition made in 1906 using a very pure maltose there was no 

 growth in the clo-sed end (fig. 145). The organism is therefore, as far as known, a 



*FiG. 144. — Old stab-cultures of Bad. Jiyaciiilhi 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. 



