Some Troubles of Winter Tomatoes. 219 



grafted into a potato plant, and tUe stock for some inches below 

 th.e union became diseased and finally died; and tkis potato stock 

 abounded in germs to all appearances like tliose infesting tlie cion, 

 but innoculations from pure cultures were not made and it is not 

 safe to say that the tomato disease can be transferred to the 

 potato. I'oiatoes were planted in 'boxes containing diseased 

 tomatoes and they did not contract the disease; and a crvjp of 

 potatoes was also grown on one of the benches in the tomato 

 house, sepai-ated from the diseased tomatoes only by a three-fuot 

 walk, and it remained healthy. Tomato plants at this distance 

 from alfected plants invariably took the disease. It was then 

 thought that the disease might be identical with the southern 

 tomato blight, described by Dr. D. iJ. Halsted, in Bulletin 1*J of 

 the Mississippi Experiment Station. Specimens were sent him, 

 when it was found that the two are distinct both in external 

 appearance and in the character of the organism, the germ of the 

 southern blight being a bacterium, while this is a micrococcus. 



All that is known further concerning the probable cause of the 

 disease will appear in the following report from i'rofessor VV. It. 

 Dudley, who has made some preliminary examinations of the 

 diseased plants: 



" I find a species of micrococcus present in limited numbers in 

 the cells of the tomato leaves, both in those which were blanched, 

 indicating the earlier stages of this disease, and in those blackened 

 by its later development, and also in the diseased fruits. More- 

 over, the external aspect of this disease — the blackening or 

 blighting of portions of the plants — in such as characterizes 

 diseases occasioned by bacteria in other plants. Nevertheless, 

 the preliminary cultm'es made did not give any results supporting 

 this theory. Steiilized nutrient agar -agar* was infected with sap 

 from the diseased tomato leaves and frtdts with no result what- 

 eyer; while similar iufection from the stem of a potato infested 

 with apparently a bacteaial disease,^ gave a cloudy-white growth 

 along the track of the infecting wire and on the smi'aoe of the 

 agar-agar which microscopical examination showed to be due to a 



* Agar-agar is a gelatinous vegetable substance used for making cultures of bacteria. 

 § This potato-stem had been grafted with a diseased tomato cion. 



