listeners.  And if any practical man ask, What is the use of the younger scholars learning anything about wild flowers, which the cultivation of the country may soon render extinct, and which are but weeds at best?—­there are two sufficient answers ready:  first, that all truth is divine, and that the workmanship of infinite skill is beautiful and worthy of the eyes which may behold it; secondly, that no mental discipline is better adapted for the young mind than this learning how to distinguish plants.  No more striking deficiency is observable, in most men, than the lack of a power to observe closely and with accuracy.  The general inaccuracy of testimony, usually ascribed to inaccuracy of memory, is in fact to be attributed to inaccuracy of observation.  In like manner, a large proportion of popular errors of judgment spring from an imperfect perception of the data on which the true conclusions should be founded.  The best remedy for this lack of clear perceptions would evidently be the cultivation of those habits of close observation and nice discrimination necessary in a successful naturalist.