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FUNGI FOUND IN POLLUTED WEST RIDING STREAMS. 
Thornhill, 
THE flora of polluted waters is characterised by an abundance 
of the lowest forms of vegetation, namely, Schizomycetes and 
Schizophycee, the blue-green alge ; as the pollution decreases 
there is an increase both in the number and variety of the higher 
forms. 
The Schizomycetes or fission fungi is the lowest group of 
fungi, and may be conveniently arranged as follows :— 
( 1. Coccacee—rounded forms. 
Bacteria proper. , 2. Bacteriacee—rod forms. 
{ 3. Spirillaceee—twisted rod 
forms. 
Sheathed bacteria. 4. Chlamydobacteriacee. 
White sulphur bacteria. 5. Beggiatoacee. 
Coloured—nonfilamentous— 
bacteria. 6. Rhodobacteriacee. 
The bacteria present in polluted waters are very numerous, 
amounting to as many as one million per cc. (twenty drops). 
They multiply by means of fission which is characteristic of 
the whole group, that is, the individual cells increase in length 
until a transverse wall is formed. The original cell is thus 
divided into two cells, and each of these functions like the ori- 
ginal, by this means rapid multiplication is brought about. 
The group of sheathed bacteria or Chlamydobacteriacee is 
distinguished from the bacteria proper by having the cell 
elements (bacteria) protected by a gelatinous sheath. This 
group contains most of the interesting lower forms of which the 
chief genera are Chlamydothrix, Crenothrix, Spherotilus, Clado- 
thrix, and Zooglea. 
Species of Chlamydothrix and Crenothrix occur as ochrey 
deposits in water and have therefore been called * iron bacteria ” 
or ‘iron alge.’ Such growths have frequently been the cause 
of serious trouble in water supplies, by choking up the service 
pipes, and imparting an unpleasant taste to the water. 
Spherotilus, Cladothrix, and Zooglea are most probably 
distinct forms of the same organism, and are all indicative of 
pollution. Spherotilus is the common fungus met. with in 
polluted streams, and its development is not restricted to 
any particular kind of pollution ; it often occurs in the warm 
waste waters from manufacturing premises. 
The next group Beggiatoacee contains the white sulphur 
bacteria, the chief species are B. alba and B. leptomitiformis ; 
* Abstract of paper read at the Sandsend Fungus Foray (Y.N.U.). 
Naturalist, 
