TENDENCIES OF NATURE TO PRODUCE. 277 
cessors, unpermitted to mingle with them, peeped from 
their retreats above, seeming almost to repine at their 
confinement ; they have bloomed their day, another race 
succeeds, and their hour will be accomplished too. This 
was so perfectly in unison with the shifting scenes of 
life, the many changes of the hour, that it seemed in- 
separably connected with a train of reflection, with the 
precepts which all nature points out — her still small 
whisperings for the ears of those that can hear them. 
The extraordinary tendency that Nature has to pro- 
duce, and the vigilant perseverance she maintains to 
occupy all substances as a soil for her productions, 
when they arrive at a state fitting for her purposes, is a 
well-known fact, and is perfectly in consistency with 
the uniform habit she preserves, of letting “ no fragment 
be lost.” All things tend upwards, from some original, 
through an infinity of gradations, though the beginning 
and termination may not always be perceived, nor the 
links of this vast chain be found. The most obscure 
plants, agarics or mucor, as far as we know, perfect their 
seed, and give birth to other generations ; but there is a 
fine green substance, observable upon the sprays of 
trees, stems of various shrubs in every hedge, upon old 
rails and exposed wood-work, leaving a powdery mark 
upon one’s coat that has rubbed against such places, 
which I have always considered as the very lowest ru- 
diment of vegetation. This matter, submitted to ex- 
amination in the microscope, presents no foliage or 
plant-like form, but appears a kind of pollen, a capsule, 
or a perfected seed, suspended on a fine fibre ; but from 
the extreme smallness of it I speak with hesitation, net 
being able to define it satisfactorily with the most pow- 
erful lens. If it be, as I have conjectured, a perfected 
seed, it probably is the origin of many of those minute 
mosses, that become rooted, we know not by what 
means, upon banks, stones, barks, &c., in such profu- 
sion ; but here all investigation ceases : by what agency 
this fine seed has been so profusely scattered, or from 
what source it sprang, is hidden from us, and we can 
no more satisfactorily conjecture, than we can account 
for those myriads of blighting insects, which so sud- 
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