78 
The Queensland Naturalist. 
July, 1920 
close up and the catch is compressed into a ball, which is 
held by the closing nets in front of the mouth. Then the 
pro leg, acting as a piston, ]}acks it into the mouth, and it 
passes down into the stomach. 
The larva industriously pursues this occupation for a 
while. Then some prevision of a future seems to dawn on 
its consciousness. Alongside of the digestive organ lie two 
cement glands, and drawing upon their contents it con- 
structs a little hut. just big enough to cover its body. L}ing 
down on its back, the hooked hand draws out a thread, fixing 
the end on the leaf or other resting place; the thread is 
drawn across the case and attached on the other side. 
Repeating this process backwards and forwards, there is 
ultimately a mummy case nrmlv cemented on its support. 
Pupa Case (X 10). | Matui'e liisecJ (Bied from Pupa). 
This work done, it is transformed into a pupa, which leads a 
resting life, while the transformation into a flying insect is 
going on. 
From the upper end eight blind tracted tubes hang. 
They abstract the oxygen dissolved in the water, and convey 
it to the insect that is being shaped in the case. In a few 
days it is complete, and the problem of passing safely 
through the whirling stream to the air is solved in a most 
ingenious but simple manner. The matured insect does 
not require so much oxygen as it did when growing, and 
the surplus collects in the pupa case. This is distended by 
the pressure of the gas and the movements of the insect 
until the pressure bursts the upper portion. The gas does 
not rise at once, but collects around the insect, whose legs 
and body offer many points of attraction. 
