244 



THE REASON WHY : 



" Or in a shady tree 



Nine maopies percli'd lament their altar'd state, 



And what they hear are skilful to repeat." MAYNWARING. 



almost any kind of food; and the digestive organs extract 

 nutriment from a great variety of substances ; the stomach being 

 intermediate between the membranous, or thinly-muscular kind, 

 peculiar to the carnivorous families, and gizzards, or strongly- 

 muscular organs which are possessed by those animals that feed 

 on hard vegetable substances. 



744. Why is the wholesale destruction of crows, as generally 

 practised by farmers, a mistaken policy ? 



Because these birds destroy an a/mazing number of grubs and 

 injurious insects, which, to all appearance, have no other enemies ; 

 their singular mode of following the course of the plough, both in 

 winter and spring, leaves no doubt of this fact. 



745. Crows are persistently destroyed, because it is believed that when they 

 search after insects in newly-sown fields, they devour, also, the grain whit h they 

 meet with in their track. This may, at least in part, be true ; but no positive proof 

 can exist of such being the case. Certain it is, that in particular parts of America, 

 where the crows were completely eradicated or driven away by incessant firing, the 

 numbers of noxious insects increased so prodigiously that the farmers, to then 

 sorrow, found the remedy worse than the disease ; the whole district agreeing to 

 suffer the persecuted crows to return, and occupy again their old quarters. 



746. Why does the structure of the magpie adapt it either for 

 a tree or a ground bird? 



Because the wings are only of 

 moderate length, which renders 

 them suitable for taking the air at 

 all angles, and also for turning. 

 The tail is also greatly developed, 

 capable of considerable action, 

 and wedge-shaped ; the first and 

 second properties being requisite 

 in the frequent ascents and 

 descents of the bird, and the last 

 in avoiding the twigs and other 

 obstacles which the bird could 



not have so well avoided, if the tail had been square at 



the end. 



