PLATE IL— BACTERIA, or SOHIZOMYCETES (Gr. schists, a splitting). 



(Fig. 8 t» offer Bvart, the rut after Dodel-Port, bated on Dr Koch's photographs.) 



Bacteria are those organisms which produce the change in organic bodies known as Putrefaction. Hay Bacteria, developed in an 

 infusion of hay, may be profitably examined first Take some fresh hay, pour hot water upon it, and allow to stand. In the course 

 of a day or two the liquid becomes turbid, due to the presence of Bacteria, and latterly it has the sme.l of decaying organic matter 

 If a drop of this liquid be examined under the highest power of the microscope, it will be found to contain Bacteria of simple form. 



Figures X 3000, except Fig. 8. 



Fig. 1. Micrococci (Gr. mikros, little; kokkos, a berry) are simply small, round, or oval cells, occurring free, or in chain-like 

 rows, or united into a gelatinous mass. They are remarkable for the bright colouring matters with which they are tinged 

 — red, blue, etc & 



Micrococcus prodigiosus— the blood-red Micrococcus— is a spherical form, appearing as blood-red, slimy drops on 

 stale potatoes, bread, damp wafers, and the like. From its sudden appearance (often arising in the course of a single 

 night) it has often been superstitiously regarded as an evil omen, as stories of "bleeding bread" or "bleeding wafers"* 

 testify. The colouring matter is insoluble in water, but may be extracted by alcohol or ether. 

 Fig. 2. A chain of Micrococci found in putrefying blood. 



This chain has probably originated from the repeated division of a single individual The single cell lengthens 

 as it grows, then forms a sort of figure of 8 preliminary to division, and this repeated again and again would give 

 rise to the chain. - ° 



Fig. 3. A gelatinous film or Zooglcea. 



This film or scum forms on the surface of putrefying fluids, and consists of a number of Micrococci embedded 

 m rows in a gelatinous material This arrangement in rows has probably been produced, as in Fig. 2, by repeated 

 division, as some are found in that conditioa 



Fig. 4. Bacteria (Gr. bakterion, a staff), or Cylindrical Forms— the two red blood-corpuscles are merely represented to show 

 relative size. 



These forms are the first found in the body after death. They are short or long rods, multiplying by transverse 

 division. 



Fig. 5. Rods from putrefying vegetable matter, with a vibratile cilium at each end, by means of which they wriggle about. 

 Fig. 6. Spirochete (Gr. chaite, hair), or Relapsing Fever Bacteria, occurring in the blood of fever patients. 



The spiral filaments are flexible and exhibit wave-like movements, which is often revealed by the motion imparted 

 to the blood-corpuscles in the neighbourhood. 



Fig. 7. Spirillum — to be found in puddles in summer where there is decaying vegetable matter. 



They form inflexible spiral filaments, of one or several turns, and have a vibratile cilium at each end 

 Fig. 8. Development of Spirillum — a to i. 



(a.) Zooglcea-stage — motionless forms embedded in gelatinous materiaL 



lb.) Vibrio-stage — bow-shaped forms passing into spiral forms. 



(c.) Filamentous-stage — the last elongated. 



(d.) Filamentous-stage — further developed forms, in which the filament is long and motionless. 



le.) Filamentous-stage — Spore-producing filament 



(/) Filamentous-stage — ripe and motile filament 



(g.) Filamentous-stage — filament breaking up. 



th.) Spores which encyst and divide to form sporules. 



(i.) Spores germinating — little comma-shaped bodies which reproduce the original Spirillum 

 Life History Diagram.— The stages are here given through which Spirillum passes in order to complete the cycle of its life. 



