Mo THE POPULAR SCIENCE MONTHLY 



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 in- 

 stinct 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 pass- 

 ing traveler to bees' nests, to call his attention to the important busi- 

 ness 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 encoun- 

 tered, they flutter up to him and point the way to a nest, and if fol- 

 lowed, 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 cor one), 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 circum- 

 stance 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 sple?idens) , by the worthy Blackwall, who 

 saw these birds " on the eastern coast of Ireland, after many unavail- 

 ing 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 posses- 

 sion of the contents." Perhaps it would not be easy, says Blackwall, 

 " to select a more striking example of intelligence among the feathered 



