166 THE MICROSCOPICAL NEWS. 
THE, BAC T-E RI ACC Bae 
By W. Biackpurn, F.R.M.S. 
HESE micro-organisms or protophytes have been the subject 
of much controversy of late years, and have often been re- 
garded in very different lights, by botanists on the one hand and 
physiological experimenters, who are not always botanists, on the 
other. They nearly all agree, however, in considering them to be some 
of the lowest forms of vegetable life ; to be usually destitute of chlo- 
rophyll, a circumstance which separates them from the Algee, and 
renders them incapable of utilizing the materials upon which 
higher vegetable organisms feed, making them dependent upon 
the assimilated compounds of other vegetable and animal bodies ; 
and they are also considered to be invariably the concomitants, if 
not the causes, of putrefaction and sometimes of disease. They 
may be regarded as the lowest forms of micro-fungi, and to consist 
of two kinds or varieties. In one of these they obtain their 
nourishment from the organic compounds of decaying substances, 
and thus fulfil a useful purpose in nature, where they are com- 
paratively harmless, and are called sapvophytes ; in the other kind 
they derive their nutriment from the organised materials of living 
bodies, where they are farasites, destroying the vital cells of their 
hosts, and causing disease. According to Prof. von Nageli, the 
compounds most readily made use of by these organisms as sources 
of nitrogen and carbon are albumen (peptone) and sugar, leucin 
and sugar, and ammonium tartrate, succinate and acetate, and 
asparagin. 
Julius Sachs, in his “Text Book of Morphological and Physio- 
logical Botany,” divides the Protophyta into those which contain 
chlorophyll, and have therefore been regarded as belonging to the 
Algze, and those which do not contain chlorophyll, viz.: the Schi- 
zomycetes (splitting-fungi, the Spal/pflanzen of the Germans) which 
include the Bacteriaceze and the Saccharomycetes, of which latter 
the yeast plant is the only well-known member, as the agent of 
alcoholic fermentation. 
The Bacteriacez are very small cellular organisms, in which the 
usual distinction between cell-wall and cell-contents is not observed. 
The cells are round, oval, or oblong, and the protoplasmic con- 
tents are either homogeneous or slightly granular. Sachs says,— 
“An enormous number of individuals usually are imbedded in a 
gelatinous mucilage, and this is especially true of the minute forms, 
the investigation of which is hence rendered extremely difficult.” 
The growth of the individual cell takes place by the increase of its 
length ; and reproduction, which is asexual, occurs by transverse 
