and Laboratory Methods. '-^'^49 



bacteria and so provides the eggs with a more favorable environment. By keep- 

 ing sea-urchin eggs in sterihzed sea water they were able to produce plutei from 

 eggs which had been kept eleven days before fertilization. The longest time 

 that Loeb and Lewis were able to keep them before fertilization, using the most 

 favorable KCN solution, was four days. Eggs survived longer in cultures inocu- 

 lated with protozoa (presumably ciliate infusoria) than in control cultures with- 

 out protozoa. The result here was again evidently due to destruction of bacte- 

 ria. The authors' final conclusions maybe quoted: "Both our own experi- 

 ments and those of Loeb show that too strong solutions of potassium cyanide, 

 and too long exposure to weak solutions, soon kill the egg. From this the rea- 

 sonable interpretation is, that the potassium cyanide is a poison to all living 

 matter, but it acts more quickly on bacteria than on sea-urchin eggs ; it is in no 

 sense a prolonger of life. From the fact that unfertilized eggs can be kept in 

 sterile sea water for eleven days or longer, it would seem that the specific mortal 

 processes of Loeb are as yet hypothetical phenomena without any definite experi- 

 mental basis." R. p. 



r 



CURRENT BACTERIOLOGICAL LITERATURE. 



H. W. CONN, Wesleyan University. 



Separates of Papers and Rooks on Bacteriology should be Sent for Review to H. W. Conn, 

 Wesleyan University, Middletown, Conn. 



Report on Diphtheria Bacilli in Well Persons, This committee, composed of a consid- 

 by a Committee of Massachusetts Associa- g^able number of bacteriologists of 

 tion of Boards of Health. ° 



high reputation, have presented, re- 

 cently, a report upon the extremely significant topic suggested in the title. The 

 fact that diphtheria bacilli may be found in the throats of perfectly healthy per- 

 sons is clearly a matter of the utmost importance in relation to the problem of 

 isolation of patients, and the report of this committee is of the greatest value in 

 its relation to the methods of procedure adopted by boards of health. The con- 

 clusions reached are briefly as follows : Diphtheria bacilli are frequently found 

 in the throats of perfectly healthy persons, the percentage varying according to 

 the different observers, largely because different bacteriologists use different 

 criteria for determining this bacillus. The percentage given ranged all the way 

 from 1.2 per cent, to 22 per cent, or even more. These instances are found 

 among well people, scattered in general among the public, but are naturally^ 

 more abundant among members of families in which there are cases of diph- 

 theria. Of the former, it is estimated, according to the percentage, that there must 

 be at least S,000 persons in the city of Boston harboring bacilli in their throats. 

 The conclusion reached by the committee is that it is quite impracticable to iso- 

 late such persons, if they are not known to have been recently exposed to the 

 disease. The presence of persons with bacilli in their throats in the families 

 that have cases of diphtheria is naturally considerably higher. The committee, 

 however, after careful consideration of the matter, conclude also that it is not 



