These reeds, the ends of which are chopped off to make them all the same length, are planted perpendicularly in the earth.

I have often explored them in the hope of finding Osmia-nests.

My search has very seldom succeeded.

The failure is easily explained.

The partitions and the closing-plug of the Horned and of the Three-horned Osmia are made, as we have seen, of a sort of mud which water instantly reduces to pap.