The Osmiae 



trembling with eagerness, extended to its full 

 length to touch the two ends of the room, how 

 can we fail to grasp the architect's grave pro- 

 blem? The Osmia is measuring; and her 

 measure is her body. Has she quite done, this 

 time ? Oh dear no ! Ten times, twenty times, 

 at every moment, for the least particle of 

 mortar which she lays, she repeats her mensu- 

 ration, never being quite certain that her 

 trowel is going just where it should. 



Meanwhile, amid these frequent interrup- 

 tions, the work progresses and the partition 

 gains in width. The worker is bent into a 

 hook, with her mandibles on the inner sur- 

 face of the wall and the tip of her abdomen 

 on the outer surface. The soft masonry 

 stands between the two points of purchase. 

 The insect thus forms a sort of rolling-press, 

 In which the mud wall is flattened and 

 shaped. The mandibles tap and furnish mor- 

 tar; the end of the abdomen also pats and 

 gives brisk trowel-touches. This anal ex- 

 tremity is a builder's tool; I see it facing the 

 mandibles on the other side of the partition, 

 kneading and smoothing it all over and flat- 

 tening out the little lump of clay. It is a sin- 

 gular tool, which I should never have ex- 



77 



