Packard.] THE population of an APPLE TREE. 179 
“I also quote from a letter on the subject, for which I am 
indebted to Dr. T. M. Brewer:— 
‘The 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 w^arbling, 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 
only 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 this—I gave the 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 see 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. I do not think the robin feeds any to its young, 
because it would never do; they are too small, and its brood 
want a big lot. I have known the robin to feed its young 
19 
