Abstract
(1) The structure of e morphologically "rough" colony
of e bacillus or vibrio is essentially similar to that
of trie "Medusa head" colony of the anthrax bacillus.
The bacteria are closely attached end to end in the
form of threads.
(2) The bacteria composing a smooth colony tend to be
separate from one another and show no characteristic
arrangement.
(3) Between these extremes are e number of intermediate
forms.
(4) These variations are paralleled by similar forms
found among the streptococci and pneumococci.
(5) The structure of e colony depends ultimately upon
physical factors and varies mainly with the degree of
attachment of the component organisms.
(6) The division of the filamentous forms composing
rough colonies is much less regular in occurrence and
position than is that of the individual bacteria
composing smooth colonies.
(7) The usually described S —» R variation appears to
consist of two separate changes, one affecting the
morphology of the organism, the other connected solely
with the nature of its capsular material or other
antigenic constituents, These may occur separately,
though a considerable degree of relationship appears
to exist.
(8) The biological significance of the morphological
variations are discussed,
