330 



Mary Davies Swarlz, 



temperature of 30° C. The extract of limu manauea is free from 

 these objections, but extensive experiment is still necessary to demon- 

 strate its powers of resistance. 



The soluble dulse pentosan is certainly decomposed not only by 

 putrefactive organisms under the most favorable conditions {e.g., in 

 meat mixtures), but by aerobes and anaerobes in solutions where the 

 carbohydrate is the chief source of nutriment. The results of the 

 four weeks' digestions are summarized in the following table: 



Dulse. 



CULTURES USED 



REDUCTION 

 OP 



feeling's 

 solution. 



ROTATION OP UNALTERED 



CARBONYDRATE AFTER 



HYDROLYSIS. 



Dulse. 



Control. 



Mixture of Faecal and Soil Bacteria 

 (aerobic) 



Mixture of the Bacilli of Malignant 

 Oedema and Symptomatic Anthrax. 



Mixture of faecal and Soil Bacteria 

 (anaerobic) 



+0.13° 



(Lost by 

 Accident) 



+0.13° 



+0.20° 

 +0.20° 



+0.20° 



In the present studies, this pentosan stands second to the galactans 

 in degree of resistance.. 



Sawamura (267) thought that he observed a slight hydrolysis of 

 mannan by B. Prodigiosus, an observation which has not been verified 

 in these experiments. No reducing substance was detected in the 

 three-day cultures nor the four-weeks cultures, in which this organism 

 was present. The opaque jelly, insoluble in water, formed from salep 

 by the action of B. Coli communis, B. Prodigiosus, and mixed cultures 

 containing these organisms, resembles an intermediary product of 

 the acid hydrolysis of salep-mannan described by Thamm (276). 

 He isolated and examined two such products, one forming an opales- 

 cent solution in water, the other insoluble, but passing over into the 

 soluble form by treatment with dilute alkali; both were anhydrides 

 of mannose. It seems reasonable to inquire whether this insoluble 

 material produced by bacterial action may not be regarded as an 

 early stage in the hydrolysis of the carbohydrate under consideration, 

 especially in view of the fact that in all the other four-week trials a 

 very definite reduction of Fehling's solution was noted, corresponding 



