E. M. Doidgb I L5 



liquefies gelatine, and grows well on agar and potato, becoming intensely 

 yellow. It does not exceed 2 jj, in length, the average being 1 1 /t ; 

 chains were observed in gelatine cultures. With cultures of this 

 organism suspended in distilled water, characteristic infections were 

 obtained in three days. The experiments, however, were made with 

 detached leaves and shoots kept moist under a bell jar, and there is 

 no record of any controls having been kept. 



A study was also made of the anatomical characters of the diseased 

 tissues. In the shoots the cortical tissues are first attacked; infection 

 then progresses in a radial direction as far as the cambium, and some- 

 times the wood is affected, the latter only in cases where infection takes 

 place before the tissues are properly differentiated. In the infected 

 tissues the cell contents slowly disintegrate and become transformed 

 into a brown substance which is not stained by ordinary aniline dyes. 

 The death of cells in the infected areas and the continued growth of 

 the surrounding parts lead to the formation of small longitudinal 

 cracks; these are frequently filled up the following year by the 

 formation of scar tissue. 



In 1894, Boyer and Lambert (2) in France described a bacterial 

 blight on the leaves and shoots of the mulberry, the external effects 

 of which were verv similar to those of the Italian blight. They isolated 

 an organism from the diseased tissues and with cultures of this they 

 reproduced the disease on healthy bushes. They named their organism 

 Bacterium mori but did not describe it. 



A paper published in Science in 1910 gave the results obtained 

 by Erw. F. Smith (8), who studied the disease in America. He was 

 unable to obtain infections with any yellow organisms which liquefied 

 gelatine but isolated a white organism which was markedly pathogenic. 

 He obtained numerous infections with pure cultures of this organism 

 and so also did several of his co-workers, working independently. 

 The organism and its effect on the host plant were described in detail, 

 and the name Bacterium mori was retained. As this organism appears 

 to be identical with the one isolated from blighted mulberry shoots in 

 this country, a detailed account of the bacterium is given elsewhere. 

 Smith concluded that either there are two organisms (Bacillus cubonianus 

 and Bacterium mori) capable of causing a blight of the mulberry, or 

 that the Italian workers secured inoculations with mixed cultures. 



In 1914, Smith (9) published a further note stating that he was 

 convinced of the identity of the French and American blights, having 

 seen when in Paris, specimens of blighted mulberry twigs collected in 



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