the samples were examined by means of dark field microscopy and 100 bacteria in randomly selected fields were classified on a percentage basis into one of the following morphological categories : ( 1 ) spirochetes , ( 2 ) motile rods , ( 3 ) filaments , ( 4 ) fusiforms , ( 5 ) straight rods , and ( 6 ) coccoid cells .
C0010851
filaments
C0007634
cells