On the other side of the outworks of the fortification, the lid and barricade, are the cells set more or less far down in the spiral, according to the diameter of the shell. They are bounded back and front by partitions of pure resin, without any encrustations of mineral particles. Their number is exceedingly restricted and is usually limited to two. The front room, which is larger because the width of the passage goes on increasing, is the abode of a male, superior in size to the other sex; the less spacious back room contains a female. I have already drawn attention in an earlier chapter to the wonderful problem submitted for our consideration by this breaking up of the laying into couples and this alternation of the males and females. Without calling for other work than the transverse partitions, the broadening stairway of the Snail-shell thus furnishes both sexes with house-room suited to their size. The second Resin-bee that inhabits shells, Anthidium bellicosum, hatches in July and works during the fierce heat of August. Her architecture differs in no wise from that of her kinswoman of the springtime, so much so that, when we find a tenanted Snail-shell in a hole in the wall or under the stones, it is impossible to decide to which of the two species the nest belongs. The only way to obtain exact information is to break the shell and split the cocoons in February, at which time the nests of the summer Resin-bee are occupied by larvae and those of the spring Resin-bee by the perfect insect. If we shrink from this brutal method, we are still in doubt until the cocoons open, so great is the resemblance between the two pieces of work. In both cases, we find the same lodging, Snail-shells of every size and every kind, just as they happen to come; the same resin lid, the inside gritty with tiny bits of stone, the outside almost smooth and sometimes ornamented with little shells; the same barricade--not always present--of various kinds of rubbish; the same division into two rooms of unequal size occupied by the two sexes. Everything is identical, down to the purveyor of the gum, the brown-berried juniper. To say more about the nest of the summer Resin-bee would be to repeat oneself.