ATTEMPTS TO CULTIVATE BACTEROIDS OF BLATTID/E. 183 



In the work of the writer on the bacteroids of the Blattidae, 

 the results of which are in manuscript, a number of attempts 

 have been made to cultivate artificially the bacteroids of Blatella 

 germanica, Blatta orientalis and Periplaneta americana. The 

 culture media employed include bouillon, agar, gelatin, sugar 

 bouillon (under aerobic and anaerobic conditions), rabbit blood 

 agar, peptone and ascitic fluid -bouillon. In obtaining the 

 bacteroids for inoculation the following technique was employed. 

 Oothecse were flamed at one end, a sterile capillary pipette 

 thrust through such flamed surface to the opposite end of the 

 ootheca, thus withdrawing material from within the unflamed 

 as well as the flamed end. This material, w^hich was shown by 

 repeated examinations to contain bacteroids, was transferred to 

 tubes of media. Cultures were also inoculated with bacteroids 

 obtained from the fat-body and ovary. Segments of the abdomen 

 were gently pulled apart by means of forceps, the intersegmental 

 membrane being ruptured. By manipulating the forceps in 

 pulling, one of the segments could be lifted away from the 

 viscera, so that when the rupture occurred the segment would 

 project like a shelf above the digestive tract with its adhering 

 masses of fat-body. With a sterile platinum needle, portions of 

 fat-body were "fished" from the under side of this shelf or from 

 the surface of the digestive tract, care being taken not to touch 

 the torn edge of the segment. By this method remarkably little 

 contamination was encountered. Many cultures remained 

 sterile, or yielded but a few scattered colonies on solid media. 



From 20 oothecse of Blatella germanica, 25 cultures were made. 

 16 of these 25 remained sterile, while in the other nine there 

 appeared a variety of organisms, none of which resembled the 

 organisms obtained by either Mercier or Glaser. Comparable 

 results were obtained in cultures from the fat-body and ovary. 

 A number remained sterile, while in the other cultures appeared 

 a variety of contaminating organisms. Attempts to cultivate the 

 bacteroids of Blatta orientalis and Periplaneta americana yielded 

 results entirely similar to those obtained with Blatella germanica. 



In the endeavor to eliminate contamination entirely, there 

 were made, in addition to the above, a number of cultures using 



