DECOMPOSITION OF PLANTS. 



ones of the forest, insects are often the primary 

 agents, yet other minute substances are commonly 

 found to accelerate or complete the dissolution. 

 JFungi in general, particularly those arranged as 

 sphseria, trichia, peziza, and boletus, appear as the 

 principal and most numerous agents, and we find 

 them almost universally on substances in a certain 

 state of decay, or approximation to it ; though there 

 are a few genera of this class which are attached to, 

 and flourish on, living vegetation. The primary 

 decline is possibly occasioned by putrescence of the 

 sap, or defective circulation, and this unhealthy 

 state of the plant affording the suitable soil for the 

 germination of the parasitic fungus ; for there must 

 be an original though inert seed, till these circum- 

 stances vivify its principle. By what means the 

 parasite finishes the dissolution is not quite obvious ; 

 but of that insidious race the byssi, of which family 

 is the dry-rot (byssus septica,) the radicles pene- 

 trate like the finest hairs into the substance, and thus 

 destroy the cohesion of the fibres. So do the 

 nidularia3, many of the agarics, the boleti, and 

 others ; and it is not unlikely that this operation is 

 the general principle of action of the whole race, 

 though not so obvious in the minuter kinds. These 

 terminators, many of which present but little cha- 

 racter to the naked eye, under the microscope we 

 find to be of various forms, though not always so 

 distinguishable from each other as the flowers of 



