Thousands and thousands of experiments have been made throughout the ages with Snail-shells of average dimensions: the thing is certain, because I find many of them to-day. Well, have these life-saving experiments, with their immense importance to the race, become general by hereditary bequest? Not at all: the Resin-bee persists in using big Snail-shells just as though her ancestors had never known the danger of the Osmia-blocked vestibule. Once these facts are duly recognized, the conclusion is irresistible: it is obvious that, as the insect does not hand down the casual modification tending towards the avoidance of what is to its disadvantage, neither does it hand down the modification leading to the adoption of what is to its advantage. However lively the impression made upon the mother, the accidental leaves no trace in the offspring. Chance plays no part in the genesis of the instincts. Next to these tenants of the Snail-shells we have two other Resin-bees who never come to the shells for a cabin for their nests. They are Anthidium quadrilobum, LEP., and A. Latreillii, LEP., both exceedingly uncommon in my district. If we meet them very rarely, however, this may well be due to the difficulty of seeing them; for they lead extremely solitary and wary lives. A warm nook under some stone or other; the deserted streets of an Ant-hill in a sun-baked bank; a Beetle's vacant burrow a few inches below the ground; in short, a cavity of some sort, perhaps arranged by the Bee's own care: these are the only establishments which I know them to occupy. And here, with no other shelter than the cover of the refuge, they build a mass of cells joined together and grouped into a sphere, which, in the case of the Four-lobed Resin-bee, attains the size of a man's fist and, in that of Latreille's Resin-bee, the size of a small apple.