14 Theory of ^Agriculture. [Jan., 



stems and the grasses. Here begins a more vigorous gro\\'th; the 

 intertwining of roots, the firm mat which is formed, together with 

 the shelter and shade which is created, favors the hitherto strug- 

 gling efforts of nature, and she now begins to plant the soil with 

 species whose trunks stretch forth their limbs to the breeze. 



The law of succession, of which we have spoken, or which 

 might be termed the law^ of progression, is much the same as that 

 of rotation, now familiar to all farmers; only nature begins with 

 the least and ends with the great — a feature which is not imitated 

 by man; for he has no time to convert a waste into a fruitful 

 field, by following nature's law strictly, the law of succession. 

 By the same plan the waters are peopled. The law of succession 

 is here as strictly followed as in the vegetable kingdom. We do 

 not, however, in these remarks intend to inculcate the idea that 

 there is an age of mosses and lichen, an age of the little exclu- 

 sively. The era begins with the little, it goes on till the great 

 are fully formed and constituted: the little live on still, and occu- 

 py their humble sphere, on various spots of earth, for there is still 

 room for them. It may be, however, that in any given period 

 marked by the commencement of the life of the little, and ex- 

 tending to a full establishment of the great, that there are closer 

 affinities and relationships between the products of this era, than 

 between those of any former or subsequent one, embracing in it 

 the same characteristic classes of beings. Geologists, in speak- 

 ing of an era of lizards, do not mean that lizards constituted the 

 whole of the living beings of that period. It may be, however, 

 that there is, as we have just said, a closer affinity among the 

 several orders which exist in an era than there is between the be- 

 ings of an adjacent era. This is a subject worthy of careful 

 study; yet it makes a digression here, and we now return to the 

 consideration of the organic matter of our soils. 



The organic matter, then, in the state of humus, or more pro- 

 perly the state termed by chemists crenic and apocrenic acids, so 

 far from being inert and inactive are the main things in a fertile 

 soil, notwithstanding the opinion of some distinguished chemists 

 to the contrary. By some cause or other, which w^e cannot ex- 



