THE SPHEGIDM. 221 



with its mandibles, and carries them off in order to construct its 

 nest. 



It begins by forming one chamber, which is hollowed out in 

 the clay brought from a distance and stuck on to a wall, and 

 as soon as it is finished the female goes a hunting, and, curiously 

 enough, selects the most dangerous, bold, and well-armed creatures 

 there are for its prey. It does not hesitate to attack spiders, 

 in fact, it rather enjoys the fight with them. Doubtless, the strong 

 sting of PelopcBus is a terrible weapon, and if it touches the spider 

 there is an end of the combat, but if not, this last insect has its 

 web at hand, threads of which it can throw with great rapidity 

 and exactness. 



The Pelopcetis is both bold and prudent, and approaches the 

 web flying carefully, and usually it manoeuvres so well that the 

 spider is stung before it can do anything ; but it sometimes does 

 happen that the spider is prepared for the attack, and the 

 Pelopceus finds its movements paralysed by some fine threads 

 being thrown over it. Then the spider encircles its enemy with 

 layers of web, and devours it. 



But it does not often happen that the Pelopceus is captured, 

 on the contrary, it usually manages to bring one, two, or three 

 spiders to its nest, according to their size. They are introduced, 

 and an ^^g is deposited close to them, and then more clay is 

 brought, and all is closed. Thus the first chamber is constructed 

 and victualled, and then the female builds a second one on the 

 side of the first and upon the same horizontal line, and fills it in 

 the same manner, then the third and the fourth cells are added, 

 and sometimes there are six or eight of them. The external 

 surface of the nest is marked with long depressions, which cor- 

 respond with the intervals between the cells. The lower part of 

 the nest is thinner than the rest, and when the larvae have 

 become full grown and have undergone their metamorphoses the 

 adult insects come out from this part and leave open holes. 



If a nest be detached from a wall before the second meta- 

 morphosis has commenced — and this is by no means an easy 

 operation, for the masonry of the Hymenoptcra is good — the 

 cells will be noticed to be occupied either by larvje or by cocoons, 

 which have been made by them after the attainment of their 



