LEAVEN - 

 “Another parable spake he unto them ; The kingdom of heaven is like unto leaven, which a woman took, and hid in three measures of meal, till the whole was leavened.” Matthew 13:33

“Like unto Leaven.—" To this parable of the leaven modern science gives a peculiar significance which was wholly unknown in the times when the parable was first uttered. Then, and until very lately, it was supposed that the leavening of  bread was caused by an inanimate material acting by purely physical processes upon the meal which it fermented. Pasteur has demonstrated, to the acceptance of the whole scientific world, that ferments are not portions of lifeless organic matter; but are actual living organisms, and that the fermentation which they occasion is a necessary consequence or manifestation of their vital activity and growth." 

The progress, unfolded from the nature of the seed, is well illustrated by the contrast between the fruit-tree of Mohammedanism, and the fruit-tree of Christianity, in Prof. Thompson's " Parables and Their Home," pp. 91-96.