The birds, in bands of a few individuals to several hundred, arrived each morning at daybreak, flying low and swiftly, and making a “swishing” sound as they cut through the air. When immediately over the rice-fields, the band would suddenly swerve as if to circle, but drop almost instantly and eat greedily without a moment’s delay. Upon seeing a flock approach, the men threw stones and shouted, often succeeding in making it pass straight over or leave the vicinity after circling once or twice. Should the birds alight, the hail of stones soon put them to rout, but not until a few grains of the much-coveted rice had been secured by each individual. As the day advanced the birds spread out over the surrounding country where they were not persecuted, and spent most of the time on the ground near the cattle and horses, often perched on the backs of the grazing animals. At nightfall they returned to the cattails, and in passing over the rice-fields again took toll from the planters. The flocks in the marshes assumed tremendous proportions, and the babble of voices resembled a rushing wind; the roar of wings, if the masses were suddenly startled by the report of a gun, was not unlike the roll of distant thunder. Before finally settling down for the night they spent some time hopping about on the mud-flats and eating minute animal and vegetable matter. Carlos S. Reed, F. Z. S., Director of the Natural History Museum, Mendoza, Argentine Republic, gives the results of his investigations as to the food of _Molothrus bonariensis_ in a paper in the _Revista Chilena de Historia Natural_, año XVII, No. 3, 1913. The following is a translation, as literal as possible, of a part of the original paper, which is written in Spanish: “In the summer of 1910 there occurred in various departments of the Province of Mendoza, a great invasion of _Isocas_ (larvæ of a lepidopteran) and in various inspections which I realized in the infected countryside I was able to confirm that a number of birds occupied themselves in eating the larvæ and adults of these _Isocas_ (_Colias lesbia_ Fabr.) and among them _Molothrus bonariensis_ predominated. “It is also a voracious destroyer of the white worm (larva of _Ligyrus bidentulus_ Fairm.) when these are exposed in ploughing furrows in the vineyards. The ‘_bicho de cesto_’ (_Æceticus platensis_ Berg) is also very much persecuted by the bird with which we are occupied. “The corn-fields suffer damages by reason of _Molothrus bonariensis_, but only during the period between the beginning of the ripening of the ear and its collection; certainly, one ought not to take this damage into consideration when, during eleven months, _Molothrus bonariensis_ has fed in the cultivated country on other products, not on maize, and among these has predominated the larva of _Chloridea armigera_, the most formidable enemy of the maize-fields.