almost as soon as the liverwort. it is singular how little warmth is necessary to encourage these earlier flowers to put forth.  It would seem as if some influence must come on in advance underground and get things ready, so that, when the outside temperature is propitious, they at once venture out.  I have found the bloodroot when it was still freezing two or three nights in the week, and have known at least three varieties of early flowers to be buried in eight inches of snow.

Another abundant flower in the Rock Creek region is the spring beauty.  Like most others, it grows in streaks.  A few paces from where your attention is monopolized by violets or arbutus, it is arrested by the claytonia, growing in such profusion that it is impossible to set the foot down without crushing the flowers.  Only the forenoon walker sees them in all their beauty, as later in the day their eyes are closed, and their pretty heads drooped in slumber.  In only one locality do I find the lady’s-slipper,—­a yellow variety.  The flowers that overleap all bounds in this section are the houstonias.  By the 1st of April they are very noticeable in warm, damp places along the borders of the woods and in half-cleared fields, but by May these localities are clouded with them.  They become visible from the highway across wide fields, and look like little puffs of smoke clinging close to the ground.

On the 1st of May I go to the Rock Creek or Piny Branch region to hear the wood thrush.  I always find him by this date leisurely chanting his lofty strain; other thrushes are seen now also, or even earlier, as Wilson’s, the olive-backed, the hermit,—­the two latter silent, but the former musical.

Occasionally in the earlier part of May I find the woods literally swarming with warblers, exploring every branch and leaf, from the tallest tulip to the lowest spice-bush, so urgent is the demand for food during their long northern journeys.  At night they are up and away.  Some varieties, as the blue yellow-back, the chestnut-sided, and the Blackburnian, during their brief stay, sing nearly as freely as in their breeding-haunts.  For two or three years I have chanced to meet little companies of the bay-breasted warbler, searching for food in an oak wood on an elevated piece of ground.  They kept well up among the branches, were rather slow in their movements, and evidently disposed to tarry but a short time.

The summer residents here, belonging to this class of birds, are few.  I have observed the black and white creeping warbler, the Kentucky warbler, the worm-eating warbler, the redstart, and the gnat-catcher, breeding near Rock Creek.