150 Dr. W. J. TuUoch. The Isolation and 



It appears, then, that there are at least three serological types of organisms 

 capable of producing a tetanising poison, but it might be justifiably argued 

 that the agglutination of Cultures 2, 4, and 5, and of 3 and 6, was due to the 

 presence of a common contaminating organism in each instance. 



To exclude such possible error, the following strains of organisms which 

 were known to be non-toxic, and which superficially resembled B. tetani, both 

 culturally and in morphological characters, were exposed to three " type 

 sera," corresponding to the three serological varieties that the foregoing 

 experiments demonstrate, and also to sera which agglutinated B. sporogenes, 

 B. 2')settdo-tetani, and an organism superficially resembling B. tetani, but 

 known to be non-toxic. This non-toxic organism and others similar to it are 

 frequently present in wounds infected with B. tetani. I shall refer to it as 

 " tetanoid bacillus No. I," as there appears to be a group of such organisms 

 which can be differentiated from B. pseudo-tetani, B. Hihler IX, and from 

 one another by serological methods. Diagram IV indicates the results 

 obtained on exposing these non-toxic bacilli to the action of tetanus and 

 other agglutinating sera. 



It is seen from this result and from Diagram I that Culture E is a mixed 

 growth of two organisms : 



' (1) Corresponding to Tetani U.S.A. (Type I). 



(2) „ ' „ Tetanoid ITo. 1. 



In the succeeding sections of the present communication those (toxic) 

 bacilli which give a positive agglutination in presence of the serum of an 

 animal immunised against Culture A (U.S.A. bacillus) will be referred to 

 as tetanus bacilli of No. I serological type, those which react in the same way 

 as Culture 2 as of the No. II serological type, and those which behave as does 

 Culture 6 as No. Ill serological type. 



IV. Examination of Organisms resembling B. tetani obtained by Direct Cidti- 

 vation of Wound Exudates in the Putrescent Medium. 



In order further to test the validity of the deductions made from the 

 result obtained on examining the non-toxic organisms, and to determine, if 

 possible, the frequency with which the various types of B. tetani are found 

 in wound exudates, I carried out the following experiment. 



Cultures from wound exudates in cases of tetanus, or from old meat 

 cultures, were made, (1) directly into the selective medium, and (2) the same 

 inocula were grown in broth under anaerobic conditions for eight days. 



The growths in the selective medium were filtered through a loose plug of 

 cotton-wool to remove detritus, centrifuged, and the deposit suspended in 



