192 MANUAL OF BACTERIOLOGY. 



produce agglutinins for several colon types; this is probably 

 due to products of bacterial growth which has taken place in 

 the meat extract before its preparation as a culture-medium. 

 Agglutinins and lysins bear no relation to one -another. 



Park* points out that the majority of bacteria do not 

 develop sufficient agglutinin in the course of the disease which 

 they cause to be detected, as in the case of tubercle, influenza 

 and diphtheria bacilli. In regard to group agglutinins he 

 shows that bacteria may produce such a large amount of agglu- 

 tinin in the course of the infection that they not only aggluti- 

 nate themselves with the blood serum from the patient, but 

 that widely different bacteria may also agglutinate with the 

 serum. Thus he found that an animal injected with staphy- 

 lococcus agglutinated the typhoid fever bacillus in the propor- 

 tion of 1-160 while, before the serum from this animal agglu- 

 tinated the typhoid bacillus in the proportion of only i-io. 

 Park gives further examples of the same sort. But on the 

 other hand, he points out that in practice such conditions will 

 not be met with, and it may be regarded as certain if the 

 typhoid reaction is obtained with the serum from a patient 

 in the proportion of 1-50 in two hours at room temperature 

 that the patient is suffering from infection with a member of 

 the typhoid-colon group is present, probably the typhoid bacillus. 



Parkf also found that bacteria cultivated on homologous 

 seraj lose their property of agglutination with the kind of 

 serum used as a culture medium, but fecover this when cul- 

 tivated upon the ordinary culture-media. Weil§ obtained a 

 culture of typhoid bacillus from an abscess in the thyroid of a 

 typhoid convalescent which did not agglutinate with the 

 patient's serum nor with other homologous sera. 



*Park. Journ. Infectious Diseases. Supplement No. 2, 1906. pp. 1-9. 



fW. H. Park. Proceedings of the New York Pathological Society. ■ Vol. IV., 

 Nos. 1 and 2. February and March, 1905. 



{See p. igi. 



§Weil. Proceedings of the New Y'ork Pathological Society. Vol. IV. 

 Nos. 1 and 2. February and March, 1905. ' 



