794 



SCIENCE 



[N. S. Vol. XXXI. No. 803 



by destruction of the fat. After three months, 

 and considerable evaporation, the fluid is more 

 or less gelatinous and somewhat brownish (the 

 ochraceous to ochraceous-buff of Ridgway, and 

 near the ochroleucous of Saccardo). In such cul- 

 tures there is always a small amount of pure 

 white bacterial precipitate and the microscope 

 shows entire absence of fat globules. Such milk 

 is translucent, strongly alkaline and not viscid. 

 At no time does the culture show any acid reac- 

 tion or any striking reduction of litmus. Purple 

 litmus milk blues promptly. 



Cohn's Solution.— J^o growth, or very scanty. 



Vsohinsky's Solution.— C<ypio\ia growth, not 

 viscid, heavy fragile pellicle, sinking readily. 

 Fluid bluish-fluorescent as early as the fifth to 

 tenth day. 



Sodium OAZoride.— Tolerates 6.5 per cent, 

 sodium chloride in + 15 peptonized beef-bouillon. 

 It also grew twice in presence of 7 per cent, 

 sodium chloride, but failed oi»ce when less co- 

 piously inoculated and did not grow in 9 per cent, 

 sodium chloride bouillon. 



Chloroform.— Grew unrestrainedly and for a 

 long time in bouillon standing over chloroform. 



Fermentation Tules.—Does not produce gas or 

 cloud closed arm in peptone water containing any 

 of the following carbon compounds: dextrose, 

 cane-sugar, milk-sugar, maltose, glycerine or man- 

 nit. Strongly aerobic. 



Indol Production.— Absent or feeble. 



]Vi*ri«es.— Nitrates not reduced to nitrites in 

 brcf-bouillon. 



Temperature Relations.— Thermal death point 

 about 51.5° C. Maximum temperature for growth 

 about 35° C. Remains alive only a short time 

 at this temperature. Minimum temperature for 

 growth below 1° C. 



Drying.— 'Ra.OieT resistant on cover-glasses— 

 alive after 30 days, and another time after 50 

 days. 



Sunlight.— Sensitive. Exposed in thin sowings 

 in + IS nutrient agar in Petri dishes bottom up 

 on ice, one half of each plate covered, seventy per 

 cent, were killed by 15 minutes' exposure, one 

 hundred per cent, by 35 minutes' exposure, and 

 ninety-five per cent, by 25 minutes' exposure. 

 Colonies on the covered side developed freely. 



The following are recommended as quick tests 

 for differential purposes: Pitfield's flagella stain, 

 peptonized beef-broth, Uschinsky's solution, Cohn's 

 solution (5 days), litmus milk, nitrate bouillon, 

 sodium chloride bouillon (5 per cent.), gelatin 

 and agar plates; inoculation bj needle-puncture 



into young rapidly growing shoots of susceptible 

 species of Morus, which should show water-soaked 

 spots in 7 days or less. 



A New Spot Disease of Cauliflower: Lucia Mc- 



CULLOCH. (Read by title.) 

 A New Tomato Disease of Economic Importance: 

 Dr. Ebwin F. Smith, Department of Agricul- 

 ture. 



In the summer of 1909 my attention was called 

 to a stem disease of tomatoes prevalent in the 

 vicinity of Grand Rapids, Mich. Microscopic ex- 

 aminations showed absence of fungi and great 

 numbers of bacteria with considerable destruction 

 of the inner tissues. Petri-dish poured-plates 

 were made from these stems and the organism 

 occurring in the plates proved to be a yellow 

 schizomyeete. Inoculations were made on July 27 

 in the open with material taken directly from the 

 stems and shaken in bouillon, and the disease 

 (gross appearance and histological phenomena) 

 was in this way reproduced in a number of large 

 tomato plants, progressing slowly, however. 

 Poured-plates made from the interior of these 

 plants demonstrated the presence of the same 

 yellow organism in enormous numbers and an- 

 other series of inoculations was made in October 

 in one of our hothouses, using sub-cultures from 

 typical colonies on these poured-plates. The re- 

 sults were the same as in case of the direct in- 

 oculations — all the plants contracted the disease, 

 became stunted and were finally destroyed by it, 

 but its progress was relatively slow, one or two 

 leaves at a time slowly wilting or yellowing and 

 shriveling; in other words, there is not that sud- 

 den collapse of the whole plant so characteristic 

 of the southern bacterial disease of tomatoes 

 (photographs were passed about showing various 

 stages of this disease as obtained by pure culture 

 inoculations). 



The bacteria are very abundant in the vascular 

 bimdles, but the brown staining is less pronounced 

 than in case of the disease due to Bacterium 

 solanacearum. 



The bacteria occur in the vascular system, but 

 also hollow out cavities in pith and bark. The 

 foliage is stunted and becomes yellowish, one leaf 

 and one branch after another slowly succumbing 

 to the disease. I am not sure whether the disease 

 begins above ground or below. Whether the fruit 

 itself shows the bacterial infection or not must 

 also be left an open question. In the field, toma- 

 toes from such plants were frequently brown 

 spotted, but the origin of this brown spotting is 

 still in some doubt. 



