THE GIANT ICHNEUMON. 543 
which they belong, and may be seen even in the dried specimens, the top ot 
their sheath slightly projecting, and their shapes plainly visible after the 
removal of a portion of the abdomen. When taken from the insect and 
placed under the microscope, they present a very pretty appearance, owing to 
the gently-curved ribs with which their sides are strengthened and decorated. 
The saws act alternately, one being pushed forward as the other is being 
retracted. Their object is to form a groove in some plant, in which the eggs 
of the mother insect can be deposited, and wherein they shall find a supply 
of nourishment in order to enable them to complete their development ; 
for it is a most remarkable fact, that after the egg is deposited in the groove 
it rapidly increases in size, obtaining twice its former dimensions. 
In the genus Cimbex, of which an example is given in the illustration, the 
larvee possess twenty-two feet, and have the power of discharging a translu- 
cent greenish fluid from certain pores placed on the sides of body just above 
the spiracles. ‘his feat they can repeat six or seven times in succession. 
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< 77 Fall 
Crabro cribrarius. Philanthus triangulum. 
When they have eaten their way to the next stage of existence, they spin a 
cocoon of a brownish colour and of a stringy, tough consistency, and either 
suspend it to the branches of the tree on which they have been feeding, or 
hide it under fallen leaves. In this cocoon they remain for a comparatively 
short time, and then emerge as perfect insects. 
The fine insect on the same illustration, which is known by the name of the 
GIANT ICHNEUMON, is an example of the next family, in which the ovipositor 
is converted into a g'mlet instead of a double saw. With this powerful in- 
strument the female is enabled to drill holes into living timber for the pur- 
pose of depositing the eggs. When they are hatched, the young grubs 
immediately begin to gnaw their way through the wood, boring it in every 
direction, and making burrows of no mean size. Those of the present 
species prefer fir and pine, and I have had specimens of the wood sent to me 
which have been riddled by the grubs until they looked as if they had 
harboured a colony of the ship-worm. 
