in natural cavities, and when the entrance is large regularly blocks the passage with mud until it will barely admit her body. The hornbills have possibly lost the cleaning instinct, if they were ever possessed of it, and the singularity of their present activities must be attributed to instinct alone.
The little honey-guides are related to the barbets, and hoopoes, rather than to cuckoos, although like many of the latter they are thought to regularly steal the nests of other birds, and never rear their proper young. But aside from this diversion, they are said to conduct the passing traveler to bees' nests, to call his attention to the important business in hand by hisses and shrill cries, and to even fly in his face "as if enraged at not being followed." That such efforts are not wholly altruistic may be gathered from the fact that they will eat the bees, grubs and honey alike. According to the accounts, the honey-guides are the "pointers" among birds, for when the woodsman is encountered, they flutter up to him and point the way to a nest, and if followed, go on and on, but halt when hot on the trail. They will also point to empty nests, or even to a domestic hive, but more significant than this, they will follow a dog, or lead the confiding traveler to a leopard, cat or snake, showing clearly that, whatever the origin of this practise, whether concerned with the instinct to sound the alarm at a common enemy, and to follow it and keep it in view, or not, we are dealing with an instinct; and probably one of very pure type.
We will close this account by giving one or two reputed instances of bird-intelligence which stand out in a marked degree from others of their kind, on account both of the acts themselves and the credibility of the witnesses. Thus Montagu, whose excellence as an observer is abundantly proved in his "Ornithological Dictionary of British Birds," states that he once saw two crows (Corvus corone), by the seashore "busy in removing small fish beyond the flux of the flowing tide, and depositing them just above high-water mark, under the broken rocks, after having satisfied the calls of hunger." It seems to me that too much has been made of this instance, since it may with equal justice be interpreted as an illustration of the instinct to hide, the circumstance of the tide being fortuitous, for it does not follow that these birds knew that the tide would surely advance and sweep away their prize. The incident, however, is interesting in relation to another, told of the hooded crow (Corvus splendens), by the worthy Blackwall, who saw these birds "on the eastern coast of Ireland, after many unavailing efforts to break with their beaks some of the mussels on which they were feeding, fly with them to a great height in the air, and, by letting them fall on the stony beach, fracture their shells, and thus get possession of the contents." Perhaps it would not be easy, says Blackwall, "to select a more striking example of intelligence among the feathered
