216 ZYGODACTYLES. 



They are much more plentiful on the clay to the north of 

 London, where the trees grow rapidly and have soft wood, 

 than in Surrey, where the soil is lighter and the wood more 

 close grained and firmer. 



The green wood-pecker has been called the "rain-bird," as 

 have several other birds that are very active, or that utter 

 their cries before rain; and as, in the summer, all birds 

 either eat insects or other animals that do, the term might 

 be extended to all the tribes. Tame poultry and geese so far 

 retain their natural instincts, as to feel that state of the 

 weather which brings out their natural food, and also to 

 express their feelings by louder, and apparently less causeless 

 cries than they utter at other times. Now, if birds which 

 feed on earth insects, feel that impulse, much more must 

 birds that feed on tree insects. The trees are wholly in that 

 air which rests merely on the surface of the earth ; and when 

 the drought begins to soften, and the larvae can come nearer 

 to the cambium of the wood, or otherwise feed without too 

 great a pinching of their tender bodies by the drying wind, 

 we might as a matter of course expect redoubled activity on 

 the part of all the grove and forest birds. 



When in May, the wind blows long, cold, hollow, and dry, 

 from the east, and the evaporation produces cold till the 

 remaining moisture is congealed into hoar-frost during the 

 night and dissipated during the day, leaving the infant leaves 

 black, and the more advanced ones sapless and shrivelled 

 when the sap stagnates in the vessels of the trees, and curdles 

 and becomes sugary, as if a premature autumn had set in, to 

 produce the fall (no, not the fall, but the adhesion) of the 

 blossoms instead of the fruit, and the congregation cater- 

 pillars, with which the birds do not much meddle, bring 

 out their millions, spin their habitations of silk, and strip 

 every leaf from orchard, coppice, and hedge, the birds be- 

 come mute in the mournful groves. Many a weary wing is 



