IOWA ACADEMY OF SCIENCES. 167 



due to the presence of living organisms which are able to sur- 

 vive the heat of baking. 



In all the cases investigated the bread was of good quality 

 when first made, and a portion of the baking had, in most 

 cases been consumed before the trouble was observed. Micro- 

 scopic examination of the slimy material from several sources 

 showed that in every case immense numbers of spore, forming 

 bacilli, were present. Morphologically they appeared to be of a 

 single species. A majority of the cells contained large spores, 

 and many spores were also noticed with no portion of the orig- 

 inal cell attached. The individual cells appeared connected 

 by a mucilaginous mass which produced the stringy condition. 

 Reference to bacteriological literature showed that apparently 

 the same fermentation has been observed by others. 



Kratschmer and Niemitowitz.* in 1889, mention an occurrence 

 of a similar abnormal fermentation caused as they observed by 

 hy Bacillis niesentericus vulgatus. Uffelman,t in 1890, found in 

 a sample of condemned rye bread a stringy decomposition due 

 to the action of bacteria. He isolated two species from the 

 sample he had, one the common potato bacillus. Bacillus mesen- 

 tericus vulgatus, and the other Bacillus lidermos (Loeffler). Rus- 

 sellt mentions a similar slimy decomposition as being the 

 cause of considerable trouble in Wisconsin. He also attributed 

 the condition to the presence of the potato bacillus. 



By newspaper notice, and direct inquiry the facts were 

 brought together as observed by quite a number who had been 

 troubled with this fermentation in the'r bread. From a study 

 of these reports, and the eight or ten cases which came under 

 my own observation, the following statements are made. 



It appears only during the summer months, and generally 

 only during the hottest part of the season. Its occurrence is 

 not dependent upon any particular method of making or bak- 

 ing the bread, as a number of methods reported, and tried, 

 gave the same condtion when the bread was placed in con- 

 ditions favorable for bacterial development It is not the 

 result of using any particular kind of yeast, as it has been 

 found where five brands of cake yeast were used, and in one 

 case of home made hop yeast. Russell^ mentions it as also 

 occurring where compressed yeast was used. 



♦A.US. d. Chem. Lab. d. k. k. oster. MlUtiirsanltiits (Jomlte, 1889. 



+ Oentralblatt fiir Bakterlologie, Bd. 8. 481. 



* Fifth Annual Report, Wis. Exp. Station, 1898. 



Sloe. Clt. 



