198 THE AUSTRALIAN NATURALIST, 
the nest. On every visit the wasp carried in her mandible 
a small pellet of mud about one-eighth of an inch in 
diameter, and about three or four minutes elapsed between 
each visit. About 18 visits were required to complete one 
cell, which is always commenced at the posterior end, and 
by continual additions of diagonal streaks of-mud, the cell 
is completed. The mud, which is collected from any 
suitable locality where it can be obtained soft, is moulded 
into small pellets by means of the mandibles. The pellets 
are then carried to the nest, where they are carefully 
spread by the mandibles after being further softened by the 
addition of the insect saliva. During the spreading the 
insect makes a continual low humming sound. In this way 
the nest is soon completed; this particular one, which was 
composed of 12 cells, taking about three days to complete. 
The wasp was not in any way disturbed by the presence 
of any one in the room, as she continually passed me in 
the course of her work without being incommoded in any 
way. On one oceasion I shifted the nest to a shelf about 
18 inches below, to see if she would locate it and con- 
tinue to work at it in its new position. On returning, to 
find the nest had disappeared, she was completely dis- 
mayed, and after a futile effort to locate the nest, which 
to all appearances was in similar position to the original 
one, she became wildly excited, and flew about the room 
in a menacing manner, so much so that in my own interest 
I replaced the nest rather hurriedly. On refinding the 
nest, she quickly calmed down, and after carefully survey- 
ing it, resumed her work as if nothing had happened. 
The number of cells in each nest seems to vary consider- 
able. In the one being described, 12 were present. In 
two other nests observed, there were three and five cells 
respectively, while some observers have recorded as many 
as 50 cells. As soon as each cell is completed, the wasp 
at once begins to provision it with the food necessary for 
the development of the wasp larvae. In this species each 
cell was stored with from three to five small spiders, all 
of which belonged to the one species, and was the com- 
monest one around the station. The spider is probably 
stung when the wasp is on the wing, and thus 
paralysed before being placed in the cell. The spiders, 
however, are only small, and are quickly devoured by the 
