The Regulative Action of Birds upon Insect Oscillations. 5 



of having been ruined by fire. Closer examination of the trees 

 most aifected showed that the branches, stripped of every vestige 

 of green, were festooned with the webbing left by the worms. 

 To the webs the withered remnants of the leaves adhered as they 

 fell, the very petioles having been gnawed oiF at the twigs. Not 

 one per cent, of the trees were uninjured, and these were invaria- 

 bly on the outer part of the orchard. Those which had been 

 attacked several years in succession were killed; and there was a 

 large area in the midst of the orchard from which such trees had 

 been removed. One did not need to enter the enclosure to learn 

 that the birds were present in extraordinary numbers and variety. 

 From every part of it arose a chorus of song more vai'ied tlian I had 

 ever heard in any similar area at that season of the year. Most of 

 the common summer residents were found there; and upon a second 

 visit in 1882 many of the migrant species likewise occurred. The 

 first collection was made on the 24th of May, 1881, and the 

 second on the 20th of the same month im the following year. 

 The season was less advanced at the time of the second collection 

 than at the first, so that the actual difference between the two was 

 probably not less than two weeks. At the first visit fifty-four 

 birds were taken, representing twenty-four species, and seven other 

 species were noted in the orchard of which no specimens were 

 obtained. On the second visit ninety-two birds were shot, repre- 

 senting thirty-one species, and four other species were seen. In 

 1881 the worms were nearly all fully grown, and many of them 

 had already entered the ground for their transformation, so that 

 the larvae were less abundant than they had been earlier. In 1882 

 most of them were about half-grown, only a few having reached 

 adult size. They were distinguishable with difficulty upon the 

 leaves of the trees; but when a large branch was shaken or jarred, 

 from a dozen to twenty would expose themselves by spinning 

 down and hanging at the end of a thread. The owner of the 

 orchard informed me that they were about twice as abundant the 

 preceding season. 



TURDID^. Thrushes. 



TURDUS JIIGRATORIUS, L. ROBIN. 



This species was abundant and nesting in the orchard. Nine 

 specimens were obtained in all, three in 1881 and six in the fol- 



