256 THE EVOLUTION OF LIFE 
A solution, that had been exposed to light for 
five weeks, the flakes of silica were found to be 
crowded with Bacteria mixed with inorganic con- 
cretions, rather more refractive, but otherwise very 
difficult to be distinguished from the many soli- 
tary micro-organisms. When these latter, however, 
have multiplied much in any one place so as to 
form groups (which were numerous) such as are 
shown in Plate IV., Fig. 11, their nature become 
perfectly plain. The Bacteria may be seen in such 
groups in different stages of development. Only one 
specimen was taken from this tube, and in that no 
other kind of organism was found. 
In another tube charged with the AA solution 
which had been exposed to light for five weeks, 
during the same period, many Bacteria and a few 
Torulae were found distributed through the flakes 
of silica; while on the surface of some of them 
there were many groups of more or less twisted 
organisms, such as are represented in Fig. 12, 
which seem to be motionless Vibriones. These 
bodies were, in other places, mixed with organisms 
such as are shown in Fig. 13, that must be 
regarded either as branching Bacilli, such as are 
depicted by Lehmann and Neumann in Pilate 
61, Fig. viii., of their ‘ Principles of Bacteriology,” 
or else as incipient specimens of Actinomyces. 
In another tube charged with the AA solution 
and exposed to light for five weeks, in addition to 
Bacteria there were found in the flakes a number 
of minute incipient Moulds, such as are shown in 
Plate V,, Fig. 14: Tp GX the title Mould seen 
