The abode of the KUSAPPI (_Collocalia fuciphaga_) is much more easy of access than that of its congener above described, as it is either placed at the bottom of a hole, or affixed to the naked rock. In shape it resembles that of the Salangane, but its walls are partially composed of stalks of plants, horsehair, and blades of grass, not woven, but cemented together with the aforesaid gelatinous secretion, by which it is also attached to the surface of the cliff. The amount of the mucilaginous substance used varies considerably, some nests being in great measure composed of it, whilst such as are formed of very pliable extraneous materials are made to a certain extent without its aid. Bernstein gives the following account of the process of building the nests of the Kusappi, and has proved the accuracy of his statements by numberless experiments, having even drawn the slimy thread himself from the bird's beak. "Shortly before the breeding season," says Bernstein, "the glands beneath the tongue of these birds become unusually distended, and present the appearance of two large swellings, which diminish considerably in size after the nest is completed. When about to make the foundation of its future abode, the Kusappi presses its tongue against the rock that is to serve for a support, and then, retiring a few paces, draws out a long gummy thread, which dries with great rapidity; this process is repeated, until a crescent-shaped mass is formed, and firmly fastened to the stone. The bird then takes the blades of grass, or stalks of other plants, one after another, from a heap it has already prepared, and cements them together by a similar operation, producing, as it turns its head from side to side, in order to draw out its thread, the undulating lines so frequently seen upon these remarkable structures, and this process is continued until the nest has assumed the necessary dimensions." The Salangane's method of proceeding is essentially similar to that adopted by the Kusappi, but, as we have already said, it builds entirely with the gelatinous threads, without any foreign admixture. We have frequently remarked that such of these birds as are well fed exhibit a much more considerable enlargement of the glands than is observable in those that have only been able to obtain a scanty supply of nourishment. This fact explains the reason why so much difference is constantly noticeable both in the size and beauty of these much-prized nests, millions of which are annually consumed, such as are very clear and delicate often realising fabulous prices. Java is particularly rich in this article of commerce, and Epp thus describes one of the localities in which the nests are most numerously met with:--"The Karang Kallong," he says, "is a huge chalk rock, rising perpendicularly from the sea, by which it is surrounded, and is garrisoned with a force of twenty-five men, whose sole duty is to protect the birds while building. A large tree grows at the edge of