May 20, 1910] 



SCIENCE 



795 



[Since the above paragraph ■wag written many 

 of our check tomatoes in hothouses have con- 

 tracted the disease, also much yoimger tomato 

 plants on neighboring benches, together with a 

 purple-flowered spiny Porto Rican weed {Solanum 

 glohiferuml) grown in the house because of its 

 reported resistance to the brown rot. Not in a 

 long time have we had such a wholesale escape 

 of a bacterial disease to our cheek plants, and 

 the indications are that the disease is readily 

 communicated from plant to plant through the 

 parts above ground, this being favored by libera- 

 tion of the bacteria through the frequent cracking 

 open of the diseased stems. We have also found 

 the bacteria abundant in the fruits of diseased 

 plants.] 



The losses around Grand Rapids, Mich., last 

 year amounted to eight or ten thousand dollars, 

 and the writer has some evidence indicating that 

 the disease is prevalent in other parts of the 

 northern United States, and has probably hitherto 

 been confused with the more rapidly acting dis- 

 ease due to Bacterium solanacearum. I suspect 

 it to be a disease of hothouses as well as of the 

 open. 



Only some preliminary notes can be offered at 

 the present time on the cultural characteristics of 

 this organism, which may be known as Bac- 

 terium ( ? ) Michiganense. Some of these char- 

 acters are as follows: 



The organism when taken from the -vessels is a 

 short rod with rounded ends, single or in pairs, 

 termo-like; taken from ten-day agar culture and 

 stained with earbol fuchsin, the majority are 

 0.35 to 0.4 X 0.8 to 1.0 m. The writer observed no 

 active self-motility when taken from the stem or 

 old agar-cultures and examined in water. On 

 staining young agar-cultures for flagella they 

 appeared to be polar, but no good preparations 

 were secured. 



In morphology, as taken from the stem, the 

 organism closely resembles Bacterium, solanace- 

 arum as it occurs in the southeastern part of the 

 United States. The organism from the stems 

 came up rather slowly in + 15 agar-plates, the 

 first colonies to appear being a few scattering 

 intruders. Afterwards the right organism ap- 

 peared plentifully in the form of pale yellow, 

 smooth, wet-shining, round surfaxje colonies not 

 unlike those of Bacterium campestre. The buried 

 colonies were small, round to broadly elliptical. 

 The intruders in this case formed wrinkled, raised, 

 gummy-looking, roundish yellow colonies. 



Agar Stabs. — Surface growth in 15 days, at 



25° C, 10 mm. in diameter, canary yellow, smooth, 

 shining, opaque, flat, viscid. Stab growth finely 

 saccate. Grows slowly on agar. 



Corn-meal Agar Stabs. — Scanty, pale yellow 

 surface growth. Moderate stab growth; better 

 than in peptonized beef-agar. 



Potato Cyliiiders. — After a month's growth 

 moderate, spreading, thin, smooth, canary yellow; 

 moderate amount of yellow precipitate in the 

 liquid which is clear, i. e., not thickened; potato 

 slightly browned. This serves to distinguish the 

 organism from Bacterium campestre and Bac- 

 terium pJiaseoli. The potato becomes alkaline to 

 litmus paper. Only a small portion of the starch 

 is destroyed. 



titrate Bouillon. — Does not reduce nitrates to 

 nitrites. 



Cohn's Solution. — No growth. 



Milk. — After fifteen days the surface of the 

 milk is yellow (canary yellow to a depth of 3 

 to 4 mm. ) . There is also a yellow rim 2 to 3 mm. 

 wide. In the lower part of the tube the milk was 

 cream color, and was not solidified. The yellow 

 layer on the surface increased in depth until at 

 the end of a month it was 10 to 12 mm. in depth 

 and yellow, the -milk below having become a deep 

 cream color, thick and smooth like butter. At 

 this time there was some yellow precipitate at the 

 bottom of the tube. In another set of test-tube 

 cultures the milk at the end of fifty days showed 

 a yellow translucent whey 12 to 25 mm. in depth, 

 the curd being deep cream color. There is prob- 

 ably a lab ferment. 



Litmus Milk. — The litmus is reduced. At the 

 end of fifteen days the medium was uniformly 

 pale gray (Saccardo's griseus) and liquid through- 

 out. After a month the litmus color had nearly 

 all disappeared, the milk being dirty cream color 

 and somewhat thickened. 



Beef Bouillon. — The appearance at the end of 

 fifteen days was as follows: Moderate clouding, 

 thin white flocculent masses suspended in the 

 medium. A moderate slimy precipitate, which 

 rises in long strings on whirling; these break 

 with shaking, but do not readily dissolve. No rim 

 or pellicle. After another three weeks, rolling 

 clouds, densest at surface, wide patches of rim, 

 no pellicle; precipitate moderate, yellowish, viscid, 

 rises in a swirl on whirling. Organism grows 

 slowly in -|- 15 bouillon. 



Gelatin Stabs. — Growth after five weeks scant, 

 canary yellow, surface smooth, shining, slight in 

 the stab, no liquefaction (temperature 14° to 

 15° C). 



