Each infecting the other.
Every time a carpenter saws fresh timber with a saw recently put through wood attacked with dry-rot, he risks infecting it with the Fungus; and similarly in pruning, in propagating by cuttings, &c.
As a teacher, besides the power of accurately gauging the character and capabilities of those who studied under him, he had the faculty of infecting them with his own enthusiasm, and thus of stimulating them to put forward their best efforts.
When the free ends of the hyphae emerge again into the air they swell up into spherical bodies which may either fall off and behave as conidia, each putting out a germ-tube and infecting the host; or the germ-tube itself swells up into a zoosporangium which develops a number of zoospores.
Infection in these cases occurs in the seedling at the place where root and shoot meet, and the infecting hypha having entered the plant goes on living in it and growing up with it as if it had no parasitic action at all.
Heteroica, is heteroecious; the ascospores infecting the leaves of Vaccinium uliginosum, while the conidia which then arise infect only Ledum palustre.
It has been shown especially in the Uredineae and Erysiphaceae that many forms which can hardly be distinguished morphologically, or which cannot be differentiated at all by structural characters, are not reall y homogeneous but consist of a number of forms which are se se s g sharply distinguishable by their infecting power.
"Dry rot," which usually attacks the sap-wood, generally starts in a warm damp unventilated place, and is caused by the growth of fungi, some of which are visible to the naked eye, some microscopic. The spores from the fungi on the decayed wood float in the air and alight on any adjacent timber, infecting this also if the conditions be favourable.
The threadworm or Oxyuris vermicularis is a common parasite infecting the rectum.
At present, there are about one hundred new cases reported per month around the world, infecting about the same number of people as die from lightning strikes.