although hot, are also healthy; and, moreover, the mosquitoes, in most places, are not in sufficient numbers to be a serious pest, although of course there must be nets for protection against them at night. The country is excellently suited for settlement, and offers a remarkable field for cattle-growing. Moreover, it is a paradise for water-birds and for many other kinds of birds, and for many mammals. It is literally an ideal place in which a field naturalist could spend six months or a year. It is readily accessible, it offers an almost virgin field for work, and the life would be healthy as well as delightfully attractive. The man should have a steam-launch. In it he could with comfort cover all parts of the country from south of Coimbra to north of Cuyabá and Cáceres. There would have to be a good deal of collecting (although nothing in the nature of butchery should be tolerated), for the region has only been superficially worked, especially as regards mammals. But if the man were only a collector he would leave undone the part of the work best worth doing. The region offers extraordinary opportunities for the study of the life-histories of birds which, because of their size, their beauty, or their habits, are of exceptional interest. All kinds of problems would be worked out. For example, on the morning of the 3d, as we were ascending the Paraguay, we again and again saw in the trees on the bank big nests of sticks, into and out of which parakeets were flying by the dozen. Some of them had straws or twigs in their bills. In some of the big globular nests we could make out several holes of exit or entrance. Apparently these parakeets were building or remodelling communal nests;
