42 INSECT ARCHITECTURE. 



satisfaction. Every time she left her nest for the pur- 

 pose of procuring a fresh supply of materials, she 

 paid a regular visit to the blossoms of a lilac tree 

 which grew near. Had these blossoms afforded a 

 supply of pollen, with which she could have reple- 

 nished her cells, we could have easily understood her 

 design; but the pollen of the lilac is not suitable for 

 this purpose, and that she had never used it was 

 proved by all the pollen in the cells being yellow, 

 whereas that of the lilac is of the same pale, purple 

 colour as the flowers. Besides, she did not return 

 immediately from the lilac tree to the building, but 

 always went for a load of clay. There seemed to us, 

 therefore, to be only two ways to explain the circum- 

 stance : — she must either have applied to the lilac 

 blossoms to obtain a refreshment of honey, or to pro- 

 cure glutinous materials to mix with the clay. 



When employed upon the building itself, tne bee 

 exhibited the restless disposition peculiar to most 

 hymenopterous* insects ; for she did not go on with 

 one particular portion of her wall, but ran about from 

 place to place every time she came to work. At first, 

 when we saw her running from the bottom to the 

 top of her building, we naturally imagined that she 

 went up for some of the bricklayer's mortar to mix 

 with her own materials ; but upon minutely examining 

 the walls afterwards, no lime could be discovered in 

 their structure, similar to that which was apparent in 

 the nest found in the wall of Greenwich Park. 



RtSaumur mentions another sort of mason-bee, 

 which selects a small cavity in a stone, in which she 

 forms her nest of garden mould moistened with glu- 

 ten, and afterwards closes the hole with the same 

 material. 



* The fifth order of Linnsus ; insects with four transparent 

 veined wings. 



