Page:Bergey's manual of determinative bacteriology.djvu/237

 :::aa. Cells longer, stalks broader.


 * 2. Stalks short, thick, not definitely in spirals.


 * B. Stalks branching in simple or compound umbels.

II. Stalks unbranched.

1. Gallionella ferruginea Ehrenberg, 1836. {Gaillonella ferruginea (sic) Ehrenberg, Vorl. Mittheil. ii. d. wirkl. Vorkommen fossiler Infusionen u. ihre grosse Verbrei- tung, Ann. Phys., Ser. 2, 8, 1836, 217; GallioneUa ferruginea Ehrenberg, Die Infu- sion thierchen, 1838, 166; Didymohelix ferru- ginea Griffith, Ann. Mag. Nat. Hist., Ser. 2, 12, 1853, 438.) fer.ru.gi'ne.a. L. adj. ferrugineus of the color of iron rust. Kidney-shaped cells. The full grown bac- teria are 0.5 to 0.6 by 1.2 to 1.5 microns. The cells secrete colloidal ferric hydroxide from the concave portion of the cell, forming band-like stalks 0.6 to 3.3 microns in width and as much as 200 microns and more in length. A rotatory motion of the cells gives rise to a spiral twisting of the stalks. In the older studies, the stalks were de- scribed as the organism, the minute cells at the tip having been dislodged or at least overlooked. The cells lie at the tip of the stalk and multiply by transverse binary fission. This gives rise to a dichotomous branching of the stalks. Stalks become very long and slender, with smooth edges. Not cultivated in artificial media. Distribution: Usually the branched stalks are attached separately in great numbers to solid surfaces. They may, however, float in irregular floes distributed throughout the water. Less commonly they form balls up to 3.0 microns in diameter. In these the stalks radiate from a center and such groups have been described as Gloeosphaera ferru- ginea Rabenhorst. In a third variety, solid tubercles richly encrusted with ferric com- pounds are formed. These are found in old pipelines or they may occur free in nature. These tubercles have been named Sphaero- fhrix latens Perfiliev. Habitat: Found in cool springs and brooks which carry reduced iron in solution; also found in wells, in storage basins in water- works and in pipe lines.

2. Gallionella major Cholodny, 1927. (Trav. Station, biolog. du Dniepre Acad, des Sci. de I'Ukraine, Classe Sci. Phys. et Math., 3, Livre 4, 1927.) ma'jor. L. comp. adj. major larger. Very similar to GallioneUa ferruginea, but the cells are distinctly larger (1.0 by 3.0 microns). Stalks are 3.0 to 6.0 microns broad. Some cells that fail to divide reach a length of 7 microns or more; these form stalks of double the normal width. The cells contain one or more vacuoles, apparently filled with an iron compound. Source: Found in springs near Krassnodar (Caucasus). Habitat: Found in iron-bearing waters.

3. Gallionella minor Cholodny, 1924. (Ber. d. deutsch. Bot. Ges., 42, 1924, 42; also see Cholodny, Die Eisenbakterien, Pflan- zenforschung. Heft 4, 1926, 47.) mi 'nor. L. comp. adj. minor smaller. Cells as in GallioneUa ferruginea, but stalks are shorter, thicker and more band- like than twisted. After division, cells do not separate as quickly as in GallioneUa ferrii- ginea. The branches gradually become en- crusted until the stalks are quite obscured. Branches of stalks are not more than 20 to 30 microns long. Source : Found in a small spring near the Biological Station in Dniepre. Also found by Beger (Ber. d. deutsch. Bot. Ges., 62, 1944, 11) in material from Camerun in Africa. Habitat: Found in iron-bearing waters.

4. Gallionella umbellata Beger, 1949. {GallioneUa ferrxiginea Palm, Svensk. Bot.