6648 Insects. 



But besides the different mode of construction of the walls of the 

 finished nest, there are two distinct types which are displayed most 

 characteristically in the embryo nests of tree-wasps. One of these 

 types is illustrated in what we may call the rose-nest belonging to 

 V. britannica, which is a rose-nest through all its stages, and the 

 other in a bell- or bottle-nest, which I only know in the embryo form, 

 and can only conjecturally assign to V. holsatica. These little bell- 

 nests are very beautiful objects. The manner in which one bell 

 hangs loosely within another, and the comb, like a clapper, inside the 

 two or three envelopes, is very peculiar. So neat and complete are 

 they in all their parts, that it might seem as if the little architect 

 never designed any further enlargement of this pretty nest. 



As to the internal structure, it may be said generally of all the 

 species, so far as I have had opportunities of observing them, that 

 they follow the same rule. The walls of the breeding-cells are made 

 of the same material as the case of the nest, but all fresh -gathered, 

 the cuttings of one part never being made up again into another part. 

 The building goes on irregularly enough, a bit being put on here or 

 there, according, as it might seem, to the taste of each builder ; but 

 the work is very regular, and hangs well together when finished ; for 

 the cells are not made separately, but each pellet is always applied 

 in three continuous lengths, namely, on two sides of one cell, and on 

 one side of an adjoining cell. This mode of construction may always 

 be traced in the finished comb, and was very distinctly seen in a nest 

 of V. germanica, where I had a large surface of comb exposed to 

 observation. The cell-wall is single, but each cell is by this mode 

 of construction worked into the adjoining cells, each having a dis- 

 tinct mucous lining of its own, the work of the grub and the plaything 

 of the adult wasp. 



But to return to our colony. As soon as the nest was closed in at 

 the bottom, a regular watch was established at the entrance. The 

 same wasp was often on duty for a long time together, but it was not 

 always the same ; and once, having caught the sentinel at her post to 

 mark her, before the operation had been completed I found that the 

 place was filled by another wasp. There she stood, with her jaws 

 extended, just inside the door-way, running forwards to exchange 

 compliments with each fresh-comer, or occasionally, when work was 

 slack, taking a walk on the outside of the nest. At night I generally 

 found one or more lying out on the nest instead of at the door, appa- 

 rently on guard. 



Yet all this time I believe that the swarm had no queen, the only 



