374 PHARMACEUTICAL BOTANY 
The iron bacteria utilize iron salts forming iron oxide which is 
deposited in a sheath around their walls. They are responsible 
for the rusty appearance of some water. 
Famiry VI.—Beccratoace& (Sulfur Bacteria).—Thread- 
like, without a capsule, but with an undulating membrane. Cell 
contents show sulfur granules. 
Threads apparently not separated, septa only faintly visible 
with iodine staining. Colorless or faintly rose-colored— 
Beggiatoa. 
The sulfur bacteria oxidize the hydrogen sulfide of sulfur 
compounds, liberating sulfur in the form of granules within the 
cell. 
ParuocEnic BacTEertiA.—Bacteria which produce diseases in 
living organisms are called pathogenic bacteria or pathogens. A list 
of some of the more important of these and the names of the 
disease caused are shown on p. 373. 
Crass II.—MyxomyceTEs, or SLIME MOoLps 
Terrestrial or aquatic organisms, frequently classified as 
belonging to the animal kingdom and found commonly on decay- 
ing wood, leaves, or humous soil in forests. Their vegetative 
body consists of a naked, multinucleated mass of protoplasm 
called the plasmodium, which has a creeping and rolling amoeboid 
motion, putting out and retracting regions of its body called 
pseudopodia. ‘The size of the plasmodium: varies from a ten-cent 
piece to several square feet of surface. It is net-like, the net 
being of irregular dimensions. Like the amoeba the outer 
portion of the plasmodium is clear and watery and known as the 
ectoplasm, the inner portion is granular and called the endoplasm. 
Like the amoeba and unlike other plants, this slimy body engulfs 
solid food by means of its pseudopodia instead of admitting it in 
solution. It is extremely sensitive to light being negatively 
heliotropic, 7.e., turning away from the sun’s rays. At the time 
of reproduction, the plasmodium creeps to the surface. The 
whole plasmodium then forms one or more fructifications. 
These fructifications vary from cushion-like masses (ethallia) 
to more elevated bodies in which the net-like structure of the 
plasmodium is preserved (plasmodiocarps) to stalked sporangia 
