The story of germ life : bacteria / by H.W. Conn.

  • Conn, H. W. (Herbert William), 1859-1917.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: The story of germ life : bacteria / by H.W. Conn. Source: Wellcome Collection.

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    chemical changes to take place in it, changes doubtless directly connected with their use of the material as food. Recognising that they do cause chemical changes in food material, and re- membering this marvellous power of growth, we are prepared to believe them capable of produc- ing changes wherever they get a foothold and begin to grow. Their power of feeding upon complex organic food and producing chemical changes therein, together with their marvellous power of assimilating this material as food, make them agents in Nature of extreme importance. DIFFERENCES BETWT5EN DIFFERENT SPECIES OF BACTERIA. AVhile bacteria are thus very simple in form; there are a few other slight variations in detail which assist in dis- slightly tapering (Fig. 9). Sometimes they are surrounded by a thin layer of some gelatinous substance, which forms what is called a capsule (Fig. 10), This capsule may connect them and serve as a cement, to prevent the separate elements of a chain from filing apart (Fig. 10 c). Sometimes such a gelatinous secretion will unite tinguishing them. The rods are some- times very blunt at the ends, almost as if cut square across, while in other sjjecies they are more round- Fio. 9.—Showing various shaped rods.