BACTERIA IN THE SOIL 173 



Both malignant oedema and symptomatic anthrax are 

 similar in some respects to anthrax itself. There are, how- 

 ever, a number of points for differential diagnosis. The 

 enlargement of the spleen, the non-motility of the bacillus, 

 the enormous numbers of bacilli throughout the body, the 

 square ends, equal inter-bacillary spaces, aerobic growth, 

 and characteristic staining afford ample evidence of anthrax. 



The Relation of Soil generally to certain Bacterial Diseases. 

 Recent investigations have, in effect, considerably added 

 to our knowledge of pathogenic germs in soil ; and whilst 

 the three species enumerated above are still considered as 

 types normally present in soil, it must not be forgotten that 

 other virulent disease producers either live in the soil or are 

 greatly influenced by its conditions. 



Frankel and Pasteur have both demonstrated the possible 

 presence of anthrax. Frankel maintained that it could not 

 live there long, and at ten feet below the surface no growth 

 occurred. This may have been due to the low temperature 

 of such a depth. Pasteur held that earthworms are respon- 

 sible for conveying the spores of anthrax from buried car- 

 casses to the surface, and thus bringing about reinfection. 

 Cholera, too, has been successfully grown in soil, except 

 during winter. The presence of common saprophytes in 

 the soil is prejudicial to the development of the cholera 

 spirillum, and under ordinary circumstances it succumbs in 

 the struggle for existence. From experiments recently 

 conducted for the Local Government Board by Dr. Sidney 

 Martin, evidence is forthcoming in support of the view that 

 the bacillus of typhoid can live in certain soils. Samples of 

 soil polluted with organic matter formed a favourable en- 

 vironment for living bacilli of typhoid for 456 days, whereas 

 in sterilised soil, without organic matter, these organisms 

 lived only twenty-three days. Tubercle also has been kept 

 alive for several weeks in soil. 



In passing, a single remark may be made in relation to 



