Germination
The first act of growth in the embryo plant. Its immediate causes are the presence of moisture, atmospheric air, and a certain temperature above freezing point, varying in elevation, of course, with the nature of the species. Heat excites the vitality of the embryo plant, and enables it to take advantage of the agents with which it is in contact. It has generally been considered that the seed should be excluded from direct light at first, but this has been proved to be quite unnecessary in very many cases.