. Carnegie Institution of Washington publication. 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 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 Smith, Bulletin 26, plate I, figs. 15-16), and at the end of 35 days this was estimated at 200 tim
. Carnegie Institution of Washington publication. 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 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 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 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 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 Bad. campestre or Bad. 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 stimulate growth. Lactose, maltos
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