Marvels of the Universe 703 
and which may be verified with a pocket lens, is that their feet have two claws, while those of the 
Social group are simple. 
Having distinguished our quarry, the next thing is to watch its movements. If there is a pump 
in the garden, that is a likely place to find the female of the species here described gathering 
materials to build her nest ; for it is built of mud. She is a wonderful worker and quickly gathers 
and carries away little pellets of moistened sand and mud which she agglutinates with mucus, 
producing a kind of mortar which she then plasters into a tube-like cell. 
The site of the nest may be the crevice of a window-frame, between the bricks and the wood- 
work ; or along the top of a doorway ; the sunny side of a summer-house is another favourite position. 
Sometimes, however, a perfectly flat wall—and even that of a newly-built house—may be used, 
the Wasp using the mortar between the bricks as a base for her work, projecting her masonry out- 
wards, as shown in the accompanying photographs. 
The cell may be from three-quarters to one inch in length, and when it is formed, the Wasp 
changes her labour and becomes a hunter, and presently you see her returning with a live cater- 
pillar, which she places inside the cell. Again and again she flies away and returns with other 
caterpillar victims until nine or more are closely packed in the cell (see photograph), together with one 
of her eggs. It should be observed, too, that although the caterpillars she places in the cell are 
alive, yet they are inactive; for when she effects their capture she stings them in some peculiar 
manner which is just sufficient to paralyse them, but does not kill them outright. In this manner 
she provides her progeny with living prey that will last it throughout its feeding period. When 
[Bu Theo. Carreras. 
THE NEST OF A MASON-WASP. 
The Wasps are here shown entering the nests. They are storing up food for the young grub, which for this species consists 
of a multitude of little green caterpillars. As many as one hundred and eighteen have been taken from a group of three cells. 
Ants are always ready to attack these Wasps, but they will never venture within the nesting-tube. 
