My glass tubes vary greatly in dimensions.

The largest have an inner width of a dozen millimetres (Nearly half an inch .-- Translator's Note.); the narrowest measure six or seven.

(About a quarter of an inch .-- Translator's Note.) In the latter, if the bottom suit her, the Osmia sets to work bringing pollen and honey.

If the bottom do not suit her, if the sorghum-pith plug with which I have closed the rear-end of the tube be too irregular and badly-joined, the Bee coats it with a little mortar.

When this small repair is made, the harvesting begins.
In the wider tubes, the work proceeds quite differently.