ON THE MOLECULAR ORIGIN OF INFUSORIA. 
53 
seen that the grouping of the molecules in twos, threes, and 
fours has become more general, and that several of these form 
new groups of eight lengthways. Many of them have melted 
together to produce longer bacteria. At the edges of the mole- 
Fig. 1 . 
a h c d e 
Fig. 1. — a, Molecular structure of the proligerous pellicle on its first appearance 
in a clear animal infusion, b, Molecular structure of the same, six hours after- 
wards. The molecules have been separated, and several are seen grouped together 
in twos and fours. Some of these have melted together so as to produce bacteria, 
which exhibit a trembling movement, c, The structure of the proligerous pellicle 
on the second day, separated. The molecules are coalescing in rows and melting 
together to form longer bacteria or vibrios, which move rapidly across the field 
of the microscope. As their development proceeds, they present the appearance 
seen in d, and in fig. 2. e, Long filaments composed of adhering molecules. 
800 diameters linear. 
cular mass, and in the fluid surrounding it, may now be seen a 
vibratile movement in the shorter bacteria and a serpentine 
movement in the longer ones, whereby they are propelled for- 
wards in the fluid — vibrio (fig. 1, c, d). From the second or 
third to the fifth or seventh days, the vibrios are lengthened, 
evidently by apposition of groups of other molecules, to their 
ends. These melt together to form a filament, which may ex- 
tend a third or half, and in a few cases entirely across the field 
of the microscope (fig. 2). 
Fig. 2. 
Fig. 2. — a, Vibrio with a serpentine movement, h. Vibrio with one flexure, 
evidently formed by the union of two bacteria, c, Elongated vibrio with one 
flexure, the area of the movement marked by a dotted line, d, An elongated 
vibrio, not moving ; a bacterium evidently added at one extremity, e, An elongated 
vibrio with two flexures, moving rapidly across the field of the microscope. An 
observation of these vital structures evidently indicates aggregations of bacteria 
and vibriones of a certain length endways, the flexures occurring at the points of 
junction. 800 diameters linear. 
The movements visible in the molecules and filaments vary 
according to the amount of development. At first those v/hich 
float loose in the fluid exhibit gyrations which cannot be dis- 
tinguished from Brunonian movements. When short bacteria 
are seen these exhibit peculiar vibrations^ — often turn round 
