Those plants which are widely distributed are generally found to be propagated from seeds which can easily be carried by the wind or by ocean currents, or form the food of migratory birds.
A gas explosion in a fiery mine may be intensified or indefinitely propagated by the dust raised by the explosion itself.
It has since been shown, however, that unless the gas is at a pressure of more than two atmospheres this wave soon dies out, and the decomposition is only propagated a few inches from the detonator.
In Italy, as long as orange trees were propagated by grafts, they were tender; but after many of the trees were destroyed by the severe frosts of 1709 and 1763, plants were raised from seed, and these were found to be hardier and more productive than the former kinds.
That the silkworm is subject to many serious diseases is only to be expected of a creature which for upwards of 4000 years has been propagated under purely artificial conditions, and these most frequently of a very insanitary nature, and where, not the healthy life of the insect, but the amount of silk it could be made to yield, was the object of the cultivator.
Airy extended Fresnel's hypothesis to directions inclined to the axis of uniaxal crystals by assuming that in any such direction the two waves, that can be propagated without alteration of their state of polarization, are oppositely elliptically polarized with their planes of maximum polarization parallel and perpendicular to the principal plane of the wave, these becoming practically plane polarized at a small inclination to the optic axis.
They mature very slowly and die after flowering, but are easily propagated by the offsets from the base of the stem.
The Vita Antonii was at an early date translated into Latin and propagated in the West, and the practice of monastic asceticism after the Egyptian model became common in Rome and throughout Italy, and before long spread to Gaul and to northern Africa.
A Simple-Harmonic or Sine Wave is the only kind which is propagated without change of form.
The alder is readily propagated by seeds, but throws up root-suckers abundantly.