I insert a straw into one of the burrows as a guide to the exploration, and with a knife carefully begin to remove the sand immediately round it. It is lined, I find, by a very delicate and slight coating of silk, no more than sufficient to keep the sand particles of its walls from falling down into the tube. I go down for an inch and a half or so and find that the tube ends blindly in a sort of silk-lined pocket, but no spider is there! This is mysterious, for I am pretty sure that my spiders are at home. I go to work upon another burrow, but this time in a different way, digging it out bodily with its surrounding sand, and placing it on a sheet of paper, with which I am luckily provided, for a detailed examination. I can now approach it from the side, and by carefully removing the sand, lay bare the whole silken tube. As before there is a straight perpendicular burrow, ending blindly, and uninhabited, but at a point at about half-way down the tube I find a branch bending upward, so that the whole tunnel is +Y+ shaped, and at the blind end of this branch I find the spider. This observation suggests that the tunnels of some of our English wolf-spiders may be more complex than was imagined. At present nothing is known of their nature in the case of other species. A little later in the summer the appearance of a troop of wolf-spiders has undergone a marked change; almost every individual will be found burdened with a circular bag of eggs attached firmly to its spinnerets, and carried about with it in all its wanderings. [Illustration: Fig. 7. Wolf-spiders; _A_, with egg-cocoons; _B_, with young on its back.] The “cocoon” is worth examination. It is a rather flattened sphere, with an equatorial line round it, giving the effect of two halves—an upper and a lower. The operation of making it has very seldom been observed, because it takes place in a closed retreat constructed for the purpose. McCook was fortunate enough to see something of it in the case of a captive _Lycosa_ which he kept in a glass jar partly filled with soil. Luckily the spider dug its tunnel for cocooning purposes up against the side of the jar, so that its interior was visible. It was about an inch deep and fairly wide, and its aperture was closed with silk. Against the perpendicular wall of soil a circular silken cushion about three quarters of an inch in diameter was spun, and the eggs deposited in the centre. The edges of the cushion were then gathered up and pulled over the eggs, and the bag thus formed was finished off with an external layer of spinning work on the two halves of the sphere, the seam or “equator” being left thin for the exit of the young spiders. The _Lycosa_ then attached the cocoon to its spinnerets and proceeded to bite away the silken sheet which sealed the burrow. The whole operation lasted about four and a half hours.