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, no 

 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, <fec., 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- 



