These _Ctenizas_ seem to be peculiarly able to adapt themselves to circumstances, for two young ones, which I sent by post to M. Lucas at the Jardin des Plantes in Paris in little wide-mouthed, cylindrical, blue glass bottles, not only lined the bottles with silk but also closed them at the mouth with a door fitting accurately into a bevelled lip, in the manufacture of both of which fragments of moss, the only material at their disposal, were used in place of earth.[151] It is curious to see how quickly the young trap-door spiders, both of the cork and wafer kinds, when taken from the nest of the mother, will make their own perfect little dwellings in captivity, and I have known them construct tube and door within fifteen hours. [Footnote 151: M. H. Lucas, in _Bull. des Séances de la Soc. Entom. de Fr._ No. 27 (1874), p. 101.] I have watched the proceedings of the young spiders, when taken from the mother's nest, in the following species: _Nemesia Manderstjernæ_, _N. Eleanora_, _N. congener_, and _N. Moggridgii_, the three first constructing wafer, and the last a cork nest. All of these very young spiders will excavate their own tubes and bring out pellets of the earth, which closely resemble those carried out from their galleries by the ants. As has been stated before, the young brood, while still in the mother's nest, will often comprise individuals of different sizes, and though the majority are no larger than the baby-spider represented at Fig. B 2, Pl. IX., _Ants and Spiders_, some may occasionally be found that are fully twice as large. The little nests which they make in captivity vary accordingly in size. Thus, out of sixteen young taken from the mother's nest (_N. Eleanora_), eleven, three days after capture, had made nests in the earth of a flower-pot, and the wafer doors of six of these nests measured 2 lines across, of four 2-1/2 lines, and of one 3 lines. The first nests of another similar lot of young _Eleanora_ spiders had wafer doors measuring respectively 2, 2-1/2, 2-1/2, 3 and 3 lines. In another case when I captured fourteen young (the entire brood found in the nest of the mother, _N. Manderstjernæ_), after the lapse of five days every one of them had made a nest, but these were smaller and more uniform, ten of the wafer doors measuring 2 lines across, one 1-1/2, and one 2-1/2. These little spiders need to be kept constantly supplied with flies, which should be killed and placed near their nests; they are often so greedy that they will attempt to drag a house-fly entire down their tubes for which it is much too large, when the door is pushed open, and the fly remains sticking in the entrance to the nest with its legs up in the air. One may even feed these spiders oneself by approaching carefully and, without causing any vibration, pushing the fly, placed on the end of a pencil, within reach of the spider.