ARCHITECTURE. 195 
instrument, with a little practice, any wasp, even 
the sentinel herself, may be picked up without 
causing a commotion. Once within the draught of 
the tube, the wasp flies up to the stop in a moment. 
It remains only to blow her down very gently, and 
catch her in gloved fingers. Then, with white 
paint, a circle, a cross, a line, or any number of dots, 
may be made on the mesothorax, out of reach of the 
wings, lest these should get smeared and clogged. 
When this has been effected, the wasp’s departure 
may be speeded by a puff from the tube, before she 
can avenge herself for the treatment she has re- 
ceived. 
By the conjoint labours of all these busy workers, 
here a little and there a little, the nest grows. The 
work of one week may have to be removed the next 
week, to make way for modern improvements and 
for the requirements of the growing city; and, as 
we have seen, it has nearly all to be done twice over. 
But wasps work very hard, and the nest grows 
visibly day by day. The little egg-shell in which it 
began is lost in the changes which the top of the 
nest undergoes. The slight strap from which it 
hung is now quite imadequate to sustain the daily 
increasing weight, and new points of attachment are 
sought to projecting roots, or stones, or branches. 
Sometimes a branch runs all through a nest, mate- 
rially adding to the difficulty of its capture. Or, 
failing these, the original point of support is strength- 
ened by layer upon layer of paper, rubbed smooth, 
and thickly coated with wasp-gum, to preserve so 
vital a point from all accidents of wind and weather. 
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