HUMUS 21 



and over ; it is nature's method to convert, transmute, disintegrate, 

 rebuild. All vegetation, all life, contributes its quota. From the 

 single-celled yeast plant floating in the wind to the majestic 

 sequoia gigantea, towering nearly three hundred feet into the air, 

 from microbe to man all have been couched in the bedding 

 ground of humus. And all eventually find their way to the com- 

 mon burial place the compost heap o$ nature to be converted 

 into humus and serve in the unbroken cycle of nature. 



For the most part, the populations of the earth dwell along 

 seashores and lakes, along rivers in the valleys, and in the low- 

 lying foothills and great plains of the torrid and temperate zones, 

 where the great humus factories of nature are located. Because 

 water runs down hill, this is so. From the dust-laden winds of 

 the desert, from star dust and the dust of disintegrating comets 

 and planets, from the weathered face of the rocks and hills and 

 mountains, nature gathers her materials, and from the mother- 

 waters of the sea she creates the rains and washes the atmos- 

 phere. And in the end, from the millions of square miles of high 

 ground, the waters find their way into all the settling basins of 

 the earth to deposit the elements of life in the humus factories 

 of nature. 



THE HUMUS FACTORY 



In her vast humus factories, nature uses many processes 

 slow combustion, chemical disintegration, bacterial decomposi- 

 tion, fermentation, heat, light, darkness, wind and rain, frost and 

 sun and earthworms; all these unite, finally to form that thin 

 surface layer of dark earth in which life is rooted. As volumes 

 have been written and are constantly being written on these many 

 processes through which nature attains her ends, we will not 

 burden these pages with detailed discussion on this subject. Suf- 

 fice it to say that many of the processes are slow, requiring years, 

 centuries, ages yes, aeons of time; for the first thin blanket of 

 parent material of humus which was spread over the surface of 



