The heap of honey and pollen in the first is twice or even thrice as large as that in the second.

In the last cells, the most recent in date, the victuals are but a pinch of pollen, so niggardly in amount that we wonder what will become of the larva with that meagre ration.
One would think that the Osmia, when nearing the end of the laying, attaches no importance to her last-born, to whom she doles out space and food so sparingly.

The first-born receive the benefit of her early enthusiasm: theirs is the well-spread table, theirs the spacious apartments.

The work has begun to pall by the time that the last eggs are laid; and the last-comers have to put up with a scurvy portion of food and a tiny corner.
The difference shows itself in another way after the cocoons are spun.
The large cells, those at the back, receive the bulky cocoons; the small ones, those in front, have cocoons only half or a third as big.
Before opening them and ascertaining the sex of the Osmia inside, let us wait for the transformation into the perfect insect, which will take place towards the end of summer.

If impatience get the better of us, we can open them at the end of July or in August.