There was no hole or crevice perceptible to the eye, nor did that portion of the bark feel less smooth than that immediately adjoining. I might be mistaken--nay, _I must be_. I had just arrived at this last conclusion, when a tiny piece of the bark was suddenly raised, and out flew the little gentleman I had seen disappear, or one too like him not to belong to the same family. The mystery was solved. Some ingenious bee-architect had devised an entrance-gate, fitting so admirably as to defy discovery when shut; while I was certain that I could lay my finger almost on the precise spot, the closest inspection failed to reveal any trace of its outline. The bark, though polished and even, was covered with faint interlaced streaks, from which even the smoothest bark is never free; and the skillful carpenter had adapted the irregular tracings of nature to his object of concealment. Wishing to inspect the workmanship without injuring its delicacy, I had to wait patiently until it should again fly open; nor was I kept long in expectation, for it presently popped up to permit the egress of another of the fraternity, and a ready twig prevented its descending. I found it designedly crooked and jagged at the edges, with an average width of about a quarter of an inch, and twice that in length; its substance was little more than the outer skin of the bark, and, being still connected at one end, opened and closed as with a spring. The cunning workman had no doubt been aware that had he made it much shorter--which the size of the passengers would have permitted--it would have required to be thrown farther back, when the greater tension would soon have destroyed the elasticity of the hinge, and, with that, its power of fitting close to the tree. Immediately within the doorway was a small ante-chamber, forming a sort of porter's lodge to the little surly gray-liveried gentleman inside, who, without quitting his retreat, showed his displeasure at my intrusion in a manner too pointed to be mistaken, and certainly manifesting neither trepidation nor alarm at the sight of one of the "lords of the creation," though probably the first offered to his inspection. From the entrance-hall, two circular tunnels conducted into the interior of the establishment, from whence came the confused murmurs of a numerous and busy community. I had just allowed the door to close, and was admiring the exceeding neatness of the workmanship, when another of the family returned home, signifying his arrival, and obtaining admittance in a manner at once novel and singular.