
FINAL DECISIVE EXPERIMENTS 265 
silica abstracted from the tube more numerous, as — 
well as longer, groups of Bacteria were seen, and 
also several incipient Moulds, whose hyphe were 
twisted and slightly branched, such as are shown 
in Fig. 22, A and B. These small Moulds were 
distinctly more numerous, and much more developed 
in this tube which had been exposed to light than 
were those taken from the companion tube, that 
had been in the incubator, and quite 35° F. hotter. 
Results obtained with Saline Solutions which had 
previously been heated im hermetically sealed 
Tubes to 125° C. (257° F.) for ten minutes. 
One of the tubes with the A solution, and heated 
as above indicated, was exposed to light for five 
weeks, when it was opened and some of the flakes 
of silica were withdrawn with a sterilised pipette. 
They were found to be crowded with Bacteria, 
isolated and in small aggregates, one of the latter 
of which is shown in Plate VIII., Fig. 23. The 
inorganic concretions distributed through the flakes 
were numerous, but quite small and often impossible 
to be certainly discriminated from isolated Bacteria 
or Micrococci. No Torule or incipient Moulds were 
found. 
A companion tube prepared at the same time 
with some of the same solution, similarly heated 
and similarly exposed to light for five weeks, was 
also examined. The flakes of silica were found to 
be absolutely crowded with very large inorganic 
concretions such as are shown in Plate XII, 
