. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. 624 THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. less also are a number of Bacteria found on the mucous membrane of the mouth. On the other hand, many ai-e associated with definite diiSeases. Spirochcete Ober- Tneieri (fig. 368 ^) is found in the blood in great quantities during relapsing fever; Bacillus anthracis (figs. 368'' and 368^) causes anthrax in cattle, &c.; and a great many other diseases—diphtheria, cholera (figs. 368 ^ and 368 ^), tuberculosis, leprosy, &c.—are associated with the a
. The natural history of plants, their forms, growth, reproduction, and distribution;. Botany. 624 THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. less also are a number of Bacteria found on the mucous membrane of the mouth. On the other hand, many ai-e associated with definite diiSeases. Spirochcete Ober- Tneieri (fig. 368 ^) is found in the blood in great quantities during relapsing fever; Bacillus anthracis (figs. 368'' and 368^) causes anthrax in cattle, &c.; and a great many other diseases—diphtheria, cholera (figs. 368 ^ and 368 ^), tuberculosis, leprosy, &c.—are associated with the activity of specific bacterial organisms. Nor must we omit to mention the numerous forms which occur in the soil, some of which are concerned in the process of nitrification, which oxidize ammonia into nitric acid, thus rendering this source of nitrogen available to higher plants, whilst others. m ® Fig. 368.—Bacteria. 1 The "Wood-portent," Mio'ococms prodigiosus. 2 Zoogloea-form of same. ' Bacterium aceti. * The same more highly magnified. »S-pirochmte eholerce asiatiae. 6 The same more highly magnified. » Bacillus anthracis and red blood- corpuscles. «The same more highly magnified. 9 Spirochcete Ohermeieri and red blood-corpuscles, m Sarcina ventrieuU 1. 2, ', 5, 7, 9 X 300; l» X 800; 4, 6, e x2000. actually fix free nitrogen, as is the case with the organism occurring in the root- tubercles of many leguminous plants (cf. p. 521). There is no doubt this organism (Rhizobium, as it has been called) can store up free nitrogen, and that leguminous plants, when associated with it, obtain nitrogen not to be accounted for as combined nitrogen obtained from the soil. Curious also is the activity of the sulphur and iron Bacteria. The former ( Beggiatoa alba) have the power of reducing the sulphates contained in the waters which they inhabit and of storing up sulphur- grains in their protoplasm; whilst the latter ( Grenothrix Kuhniana), not uncommon in
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbotany, bookyear1895
