May 24, 1907] 



SCIENCE 



807 



4. Normal feces in a large percentage of 

 cases caused a marked decomposition of the 

 egg-meat medium. In a large number of 

 such cases the Bacillits putrificics of Bien- 

 stock was observed to be responsible. In 

 at least 25 per cent, of the stools examined 

 the bacillus of malignant oedema was pres- 

 ent, though in small numbers. The 

 amount of feces tested at one time varied 

 from 2 to 32 milligrams. The Bacillus 

 aerogenes capsulatus of "Welch was found 

 to be present constantly when the quantity 

 of feces examined was at least 32 milli- 

 grams. In 2 milligram quantities, how- 

 ever, it failed to reveal itself in at least 50 

 per cent, of the tests that were made with 

 such small amounts. 



A Study of the Variation in the Biochem- 

 ical Reactions produced by Ctdtures of 

 the Colon Type: Stephen DeM. Gage. 

 The study was made to ascertain how 

 closely the variations in the intensity of 

 certain biochemical functions of cultures 

 usually included in the colon group by 

 routine tests would agree with the law of 

 biological variation. 



About 200 cultures of the colon type, as 

 interpreted at the Lawrence Experiment 

 Station, were examined after incubation at 

 40° C. for the amount of gas produced in 

 dextrose broth in 24 and 48 hours, for the 

 proportion of CO2 in that gas, and for the 

 amount of ammonia and of nitrites pro- 

 duced in nitrated pepton solution in 24 

 hours. 



The amount of gas produced in 24 hours 

 varied between 15 per cent, and 100 per 

 cent., about four fifths of the cultures pro- 

 ducing between 40 and 70 per cent, of gas. 

 After 48 hours' incubation the amount 

 of gas also varied between 15 per cent, and 

 100 per cent., and the distribution of the 

 cultures among the different gas values was 

 more uniform than at the end of 24 hours, 

 about half of the cultures producing be- 



tween 35 per cent, and 50 per cent, of gas. 

 With 15 per cent, of the cultures the 

 amount of gas increased between the first 

 and second day, while with 65 per cent, of 

 the cultures there was a decrease in the 

 amount of gas on the second day. 



The amount of CO, in the gas at the end 

 of 48 hours varied from none to 75 per 

 cent., about three fourths of the tubes con- 

 taining between 10 and 25 per cent, of 

 CO,. 



In the nitrated pepton solution at the 

 end of 24 hours about 30 per cent, of the 

 tubes contained less than one part per 

 million nitrogen as ammonia, and about 

 half of the tubes contained between one 

 and three parts, while about one fourth of 

 the tubes contained less than one part 

 nitrogen as nitrites, and about half of the 

 tubes contained between one and three, 

 parts. 



The number of determinations was alto- 

 gether too small to plot curves of biological 

 variation with any degree of accuracy. 

 The curves plotted, however, appear to be 

 simple, unimodal curves, and indicate that 

 the group was a true biological group and 

 that the variations were normal biological 

 variations. 



Involution and Degeneration Foims of 



Bacteria: D. H. Berget, M.D. 



The indefinite and confusing definitions 

 of the nature of involution and degenera- 

 tion forms of bacteria found in most text- 

 books on bacteriology are bewildering to 

 the student, and leave him in doubt as to 

 the exact significance of these terms. 



The term 'involution forms' is defined 

 in the Standard Dictionary as ' certain 

 swollen, bladder-like and irregular forms 

 which the organisms sometimes assume 

 after their death, or as the result of dele- 

 terious influences, such as insufficient nutri- 

 tion.' This definition is sufficiently clear, 



