The ants have just reached the point at which most of our African tribes have halted. Every evening they shut up their dwelling-places with immense labour--renewed daily--and by a little, unsubstantial lattice-work, which does not relieve them from the necessity of planting sentinels. It is true, however, that these great, valiant, and well-armed peoples have no fear of invasion, and, like Lacedæmon, need neither walls nor ditches. Their proud intrepidity has set limits to their industry. On the other hand, the poor artisan which lives by itself, and is always exhausted by the incessant toil of spinning and weaving, cannot rely upon its valour. It has need, in certain countries and under certain alarming conditions, of profound ingenuity, and has discovered this little miracle of prudence and combination, which eclipses both the savage and the insect. I do not refer to the great animals, none of which, except the beaver, are very industrious. In the neighbourhood of Lucerne we for the first time saw the house of the spider (the _Agelena_). It was a kind of sheath, and very well made, with a vestibule facing the south, which expanded outward like a funnel. This exterior portion, forming a little sunny retreat, was the snare and the citadel. The lady of the house stationed herself quite at the bottom of the funnel; but behind this very bottom, at the lower extremity of the case or sheath, was constructed a back apartment, small and very secure, in a white substantial cocoon. In this she trusted so completely, that while we detached the silken cables which moored the entire edifice to the bush, she made no attempt to escape. We had neither destroyed nor damaged, but simply detached the dwelling, and on the day following we found it repaired and moored to the bush on every side. The exposure was no longer so favourable; but, undoubtedly, the workman, in an advanced season of the year (in September, and under the Alps), did not possess the resources for recommencing this grand summer-work. In the Brazilian forests a little spider has its case suspended exactly in the centre of its web; and thither it hurries at the slightest approach of danger, and has no sooner entered, says Swainson, than the door suddenly closes behind it by a spring.