The explanation of the most striking features of the Dendrocolaptidae, their monotonous brown plumage, diversity of structure, versatile habits, and the marvellous development of the nest-making instinct which they exhibit is to be found, it appears to me, in the fact that they are the most defenceless of birds. They are timid, unresisting creatures, without strength or weapons; their movements arc less quick and vigorous than those of other kinds, and their flight is exceedingly feeble. The arboreal species flit at intervals from one tree to another; those that frequent thickets refuse to leave their chosen shelter; while those inhabiting grassy plains or marshes study concealment, and, when forced to rise, flutter away just above the surface, like flying-fish frightened from the water, and, when they have gone thirty or forty yards, dip into the grass or reeds again. Their life is thus one of perpetual danger in a far greater degree than with other passerine families, such as warblers, tyrants, finches, thrushes, &c.; while an exclusively insect diet, laboriously extracted from secret places, and inability to change their climate, contribute to make their existence a hard one. It has been with these birds as with human beings, bred in "misfortune's school," and subjected to keen competition. One of their most striking characteristics is a methodical, plodding, almost painful diligence of manner while seeking their food, so that when viewed side by side with other species, rejoicing in a gayer plumage and stronger flight, they seem like sober labourers that never rest among holiday people bent only on enjoyment. That they are able not only to maintain their existence, but to rise to the position of a dominant family, is due to an intelligence and adaptiveness exceeding that of other kinds, and which has been strengthened, and perhaps directly results from the hard conditions of their life.