176 BACTERIA IN RELATION TO PLANT DISEASES. 



(14) In Agapanlhus leaves 26 days after inoculation the bacilli and filaments of the Siberian plague were found 

 showing great changes. On the unstained slides their color was somewhat yellowish and they were noticed on account 

 of their refraction which was like glass or galena. These threads were two or three times the diameter of normal fila- 

 ments and they were constricted, i. e., they had lost their normal filamentous form. 



(15) Sowings of infected parts of the leaves of agapanth on nutrient gelatin or boiled potatoes on the sixteenth 

 and forty-second day after inoculation gave a typical culture of the Siberian plague bacillus. 



(16) The inoculation into mice of portions of similar leaves 16 and 42 days after the inoculation of the plant 

 caused the death of the animals from the Siberian plague. 



(17) The typhoid fever bacillus multiplied in the leaves of wheat and agapanth only during the course of the 

 first days after inoculation, gradually dying out. This dying out was shown [a) by its not taking Loefiler's or Ziehi's 

 stain, (6) by the presence of involution forms, (c) by its failure to grow in cultures. 



(18) Of all the microbes investigated B. prodigiosus multiplied most energetically and after the manner of the 

 Siberian plague, that is, in the intercellular passages and in the living cells adjacent to the point of inoculation. 



(19) The dying out of B. prodigiosus was not noticed even at the expiration of 32 days from inoculation. On this 

 date transfers from inoculated parts of the leaf into nutrient gelatin and boiled potatoes gave a typical culture. 



(20) Plants in the course of their growth may mechanically throw out the microbes from shallow layers to the 

 surface. 



(2 1 ) When wheat is grown on soil infected by disease-creating microbes many of the microbes may enter into the 

 root-system, the smaller ones getting in the easier. 



(22) When wheat is grown on soil infected by a mixture of microbes all of them may be found in the tissues of 

 the root. 



(23) The passage of the microbes from the infected roots of wheat into the stems and leaves was not observed. 



Russell (p. 6) states that he could not confirm Lominsky's results with Bacillus prodi- 

 giosus, to wit, the production of red spots and stripes in the injected plants, but inasmuch 

 as he did not experiment with the same plants as Lominsky, his experiments can not 

 be considered as a refutation of I^ominsky's statements. 



Russell also states that he failed to verify some of the results obtained by Lominsky 

 with animal parasites injected into plants, but here again his experiments are not strictly 

 comparable since he used different plants. 



He also obtained different results from watering the soil with "dilute infusions of the 

 different germs." In this case Russell does not state what plants he used, but presumably 

 not wheat, from a remark on the following page — "This result would have been much 

 more convincing had he [Lominsky] used larger plants than wheat." 



Russell found Bacterium pyocyaneum present in large numbers at the point of inoculation in 

 begonias after 69 days; in geranium after 32 days, and in Penthorum after 36 days. The anthrax 

 organism was absent from geranium {Pelargonium) at the point of inoculation after 38 days, and was 

 only sparingly present in lima bean after 1 1 days and in Echinocacius after 5 days. Staphylococcus 

 epidermidus albus was not recovered from the point of inoculation in geranium after 40 days. Staphy- 

 lococcus pyogenes aureus was also dead in geranium after 42 days, but was recovered very sparingly 

 from lima bean after 13 days. B. cholerae gallinarum was moderately abundant in geranium after 18 

 days. The organism of Schweineseuche was present in large numbers in geranium after 17 days. The 

 diphtheria organism was not found in geranium at the point of inoculation after 10 days. He has 

 the following paragraph on the result of his experiments with Bacillus amylovorus and Bacterium 

 avenae. 



' 'The pear-blight germ grown in a begonia-plant for 30 days showed at end of that time large 

 numbers at inoculation point, but not distributed throughout the plant. The same result was found 

 when injected into Phaseolus vulgaris for 30 days, also in Ph. lunatus for 16 days. In Tradescantia 

 alba, no trace could be found at the end of 60 days' incubation in this tissue. Bact. avenae was injected 

 into tissue of begonia, onion, corn, wheat, and squash, but in no case was any pathological change 

 macroscopically observable. The bacilli were not killed out in the plant-tissue, however, as they were 

 isolated from begonia and squash in large numbers, after 30 days' incubation in these tissues, but 

 their presence was confined to the tissue contiguous to point of introduction." 



Concerning the general conclusions to be drawn from his own observations, Russell 

 has the following: 



"The results of the foregoing inoculation experiments made with various forms of micro-organ- 

 isms, saprophytes as well as parasites (both for animals and vegetables), show that these germs in 

 many cases are able to live in the plant-tissues for a considerable length of time. A number of the 

 different forms, particularly saprophytes, are able to grow and spread throughout the plant to a 

 limited extent. Of the parasitic species tested, very few showed any tendency to thus spread. Even 



