COLLECTING AND REARING 41 
(to cut the cloth) and folding tongs (to close the seams). A suitable 
size is eighteen inches square, and a square yard cuts four cages. To 
make a cage, opposite edges of the cloth are laid flat and 
twice folded together (making a tinker’s ‘“‘hem’’). This 
(opened out) makes a wirecloth cylinder. Then the ends 
are cross-folded in a similar manner to close the cage. 
One of these endfolds may be opened and closed by hand 
for introduction or removal of specimens. The woven 
edge should be at the top to prevent pricking fingers on 
wire ends. Anyone can make a cage of this sort with his 
own hands, in a few minutes. 
Such a cage half immersed in the water gives a good 
foothold and plenty of room for transformation. If placed a little 
aslant, any adults that flutter and fall into the water can crawl up and 
out of it again. 
There are mishaps in plenty that may happen to rearing cages when 
placed out in the field. We believe we have encountered them all. 
A few precautionary measures will save valuable specimens. Losses 
from sudden changes of water level may be avoided by attachment 
of cages to a float. When set in a stream, losses of cages from being 
swept away by flood waters may be prevented by anchoring them 
with a wire to the shore. Losses from vandals and ignorant meddlers 
are most frequent and hardest to control; but we have found that a 
very dirty (paint smeared) piece of cloth spread over the cages, hiding 
them, will often keep the meddler’s hands off them. It is in the field 
where conditions are quite natural, and where nymphs can be caged 
as soon as captured, that the most successful rearing work can be done. 
It can, however, be done indoors. A row of pillow cages may be 
set In an aquarium, or in a deep pan of water in a sink, and a trickle 
of fresh water from the tap allowed to flow through. Grown nymphs 
if introduced uninjured will usually transform under these conditions. 
Rearing cages should be visited every morning and the adults that 
have appeared should be placed singly with their cast skins in paper 
bags (small grocer’s bags are excellent), and left there until their color 
are well developed and their chitin is hard; else pale and shrivelled 
specimens will result. 
Most of the larger dragonflies transform very early in the morning. 
By searching the shores at daybreak, many of them may be taken in 
transformation. Teneral adults and the skins from which they have 
just emerged may be found together. Sufficient material for identify- 
ing nymph and imago may thus be obtained very easily. Each limp 

Fig. 21. A 
pillow cage. 
