The host response is the defense mechanism of the host against exogenous microorganisms.

In terms of technology, today's media and that of the 19th century are worlds apart, but they still serve the same purpose.

The repeated exposure, over decades, to most taxa here treated has resulted in repeated modifications of both diagnoses and discussions, as initial ideas of the various taxa underwent—often repeated—conceptual modification.

The zonal distribution of soils developed under continental climates was first reported by Dokuchaev, who established in 1883 a map of isohumic curves, between the boreal and sub-arid zones of European Russia.