Packard] THE POPULATION OF AN APPLE TREE. 179 



"I also quote from a letter on the subject, for which I am 

 iiulebted to Dr. T. M. Brewer:— 



'Tlie most noticeable of all the destroyers of the canker 

 worm is the common cedar bird, which devours them to an 

 extent perfectly enormous. Next is the purple grakle which 

 also feeds on them as long as they last. The house pigeon, 

 if in any numbers, is an invaluable bird. See, for instance, 

 a garden corner of Summer and Chestnut streets, Salem, 

 where the pigeons make canker worms a thing unknown. 

 Among the other birds, all excellent so far as they go, are 

 the chipping sparrow, the song sparrow, the purple finch, all 

 the vireos, white-eyed, red-eyed, yellow-throated, solitary 

 and warbling, the king bird, the cat bird, the downy wood- 

 pecker, the summer yellow bird, Maryland yellow throat, the 

 blue-bird. The bluejay eats their eggs in the winter, so 

 does the chickadee. The latter eats their grub also and the 

 worm too. The common gray creeper, which is with us 

 onl}' in the winter, eats the eggs. 



'Last summer I had a nest of golden-winged woodpeckers 

 breeding on my place at Hingham. Some of them dug into 

 my barn and passed the winter. Only a part of my trees 

 were protected by a belt of printers' ink and some of them 

 were partially eaten, but this winter very few grubs have as 

 yet shown themselves, and I give my friend, Colaptes aura- 

 tus, the credit of all this. I know tliis — I gave tlie young 

 ones a lot of worms myself and they ate them as if they 

 were used to them. The old birds were too shy to permit 

 me to sec their good deeds. 



'I think the golden robin feeds its young with them as 

 long as they last, but I am not sure that they eat the tent 

 caterpillar. I nearly forgot the two cuckoos, yellow-bill and 

 black-bill. They eat every form of caterpillar, canker worms 

 included. 1 do not think the robin feeds any to its j-oung, 

 because it would never do ; they are too small, and its brood 

 want a big lot. I have known the robin to feed its younfr 



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