OBSERVATIONS ON BIRDS. 399 



very common with us ; but I cannot make out the three different 

 species of willow-wrens which he assures us he has discovered. 

 Ever since the publication of his History of Selborne I have used 

 my utmost endeavours to discover his three birds, but hitherto 

 without success. I have frequently shot the bird which " haunts 

 only the tops of trees, and makes a sibilous noise," even in the 

 very act of uttering that sibilous note, but it always proved to be 

 the common willow wren or his chiff-chaft. In short, I never 

 could discover more than one species, unless my greater petty- 

 chaps, sylvia hortensis of Latham, is his greatest willow wren. 



MARKWICK. 



FERN-OWL, OR GOAT-SUCKER. 



The country people have a notion that the fern-owl, or churn- 

 owl, or eve-jarr, which they also call a puckeridge, is very injurious 

 to weanling calves, by inflicting as it strikes at them, the fatal 

 distemper known to cow-leeches by the name of puckeridge. 3 

 Thus does this harmless ill-fated bird fall under a double impu- 

 tation which it by no means deserves in Italy, of sucking the 

 teats of goats, whence it is called caprimulgus ; and with us, of 

 communicating a deadly disorder to cattle. But the truth of the 

 matter is, the malady above-mentioned is occasioned by the cestrus 

 bovisj a dipterous insect, which lays its eggs along the chines of 

 kine, where the maggots, when hatched, eat their way through the 

 hide of the beast into the flesh, and grow to a very large size. I 

 have just talked with a man who says he has more than once 

 stripped calves who have died of the puckeridge j that the ail or 

 complaint lay along the chine, where the flesh was much swelled, 

 and filled with purulent matter. Once I myself saw a large rough 

 maggot of this sort squeezed out of the back of a cow. 



These maggots in Essex are called wornils. 



The least observation and attention would convince men, that 

 these birds neither injure the goatherd nor the grazier, but are 



3 The goat-sucker, like other birds, finds insects in attendance on cattle ; 

 hence its apparent "striking at them." Magpies and starlings will coolly perch 

 on the backs of animals and leisurely make their meal. 



