1886 The Zoologist— October, 1869. 



rid of their winged foes, little thinking that they had other foes in 

 their place whose approach was more difficult to detect. In the 

 second year many fields of wheat suflfered from wire-worm ; but in the 

 third their ravages had become so general throughout the district 

 as to occasion serious alarm. Little could be done to suppress their 

 numbers until the rooks were again thought of, and the evil was 

 traced to its source. The rookery was permitted to be re-established 

 by the return of many who had escaped the massacre, and who still 

 cherished a partiality for their native trees, but who had hitherto been 

 continually driven off: their rapidly increasing numbers soon reduced 

 the insect pest, leading the farmers to acknowledge the error into which 

 they had fallen, and henceforth to look upon the rook as a friend in- 

 stead of an enemy." — p. 134. 



The green woodpecker is an especial favourite of mine : as regards 

 colour he is the most beautiful of British birds, and he is a faithful 

 friend to the proprietor of forestry by his incessant efforts to alleviate 

 the plague of carpenter caterpillars, and the mysterious jarring noise 

 he makes during his researches with this object are too familiar to 

 need description. Mr. Sterlaud has discovered another and very 

 different sound which this bird produces ; and has detected the exact 

 manner in which the feat is performed. I will quote the passage. 



Tlie Green Woodpecker. — " I have remarked previously that nearly 

 all the old oaks in the forest have suffered the loss of their tops by the 

 agency of wind and lightning, aided by natural decay. Sometimes 

 you may see the upper portion of one of these venerable trunks quite 

 denuded of its bark, and riven with many fissures, though the tree is 

 all the while in vigorous growth. On some of these I have often 

 noticed the green woodpecker practise a singular feat. Placing its 

 bill in one of the long cracks I have mentioned, it produces, by an 

 exceedingly rapid vibratory motion, a loud crashing noise, as if the 

 tree was violently rent from top to bottom. I have heard it when the 

 sound was so loud and sudden that the woods rang again. For a 

 long time I was at a loss to know how it was produced, but 1 one day 

 witnessed the process, and have seen it several times since : it would 

 effectually rouse up all the insects, for it seemed as if the tree 

 quivered from top to bottom." — p. 144. 



Mr. Sterland disposes of the Baldamus theory about cuckoo's eggs 

 in what may be called a very jaunty manner. " I believe that what 

 Dr. Baldamus supposed were cuckoo's eggs were only abnormally 

 large ones of the birds in whose nests they were found, and this varia- 



