FUNGI.—BACTERIA. 387 
nutrition ; in this, and in that they do not contain chlorophyll, 
they resemble Fungi, and should doubtless be considered as 
Fungi, unless, indeed, they belong tothe lowest group of animals, 
viz., Monads, as is maintained by some observers. Whether all 
Bacteria have an envelope of 
cellulose is questionable, for as Fic. 849 
their structure cannot be made ine 
out except under the highest a 
powers of the microscope, what ,, / 
appears to be cellulose may Uo i p i 
really be nothing more than a 9 i; 
halo produced by improper il- G / 
lumination, indifferent staining, ) / 
and other causes. The forms of 
Bacteria vary considerably, some Fig. 849. Bacilli, showing development 
being small spherical bodies, BrOR BEG Ee odes esan Teh 
which may exist singly, or in 
chains, or in masses, Micrococci (fig. 850, 5, 6, and 7) ; others are 
somewhat oval in form, Bacteria (jig. 850, 2) ; others, again, rod- 
shaped, Bacilli (fig. 849) ; while some have the form of a cork- 
screw of one or more turns, Spirilla (fig. 850, 3 and 4), &c. Most 
of the Bacteria are motile, the source of movement in many forms 
Fic. 850. 
awe | 
rele) 
°° 90 Fig. 850. 
oe 1, Sarcine. 
2. Bacteria. 
3. Spirilla, 
4, Spirillum, show- 
ing flagella, 
Micrococci in 
{ strings, singly 
andin groups. 
.| After Cohn 
and Sachs. 
sO ES) 
being flagella, generally one at each end (jig. 850, 4), while in 
others the cause of movement has not yet been discovered. 
Bacteria may be divided according to their morphology or their 
physiology, some producing coloured secretions, chromogenous, 
although they themselves are colourless ; others causing fermen- 
tation, zymogenous ; while others are most probably the cause 
of disease, pathogenous. It is this last group which has been 
creating so much interest lately in connexion with phthisis, 
cholera, hydrophobia, anthrax, &c. The methods of reproduc- 
tion are fission, and in some cases the production of spores, 
though both methods are most probably ayamogenic. in 
co2 
