ORDER VI.——-VEIN-WINGED INSECTS. 237 
of expense and trouble might be saved to our home manu- 
facturers. For such purposes they should be collected ear- 
ly in the spring or late in the autumn, as those which are 
perforated with holes would be of no use as a dye-stuff. 
The Cynips seminator is one of the smallest of the gall- 
wasps, and yet the oak-ball, which is the consequence of its 
puncture, is as large as a walnut, of a reddish color and a 
rough exterior. Each one of these galls contains a large 
number of maggots, and when it is ripe, or rather when it 
has been abandoned by the perfect insects, it is found to 
contain a soft, spongy, and dry substance, like a toad-stool, 
which is easily broken and reduced to powder. 
A great number of different species of Gall-wasps are 
found in all parts of the world, and their increase is only to 
be desired, not dreaded, for, with the exception of the saw- 
wasps, they do no injury to vegetation, but, on the con- 
trary, are very useful to man; as, for instance, those which 
produce the oak-apples of commerce (Cynips Galle tinctorie), 
found upon the dyer’s oak (Quercus infectoria), in the Le- 
vant. 
The IcHNEUMON-wasps are another very useful and in- 
teresting tribe of vein-winged insects. They are distin- 
guished by their slender body, long ovipositor, and long an- 
tenn, which are always in a continual quivering motion. 
They deposit their eggs in the living body of other insects, 
such as grubs, caterpillars, and all kinds of larvae, upon 
whose substance they feed. Although able to pierce cater- 
pillars, grubs, and cocoons, yet they never use their ovi- 
positor for defense, and consequently can be handled with 
impunity. 
The larger ichneumons deposit only one egg in each lar- 
va, as in the caterpillar of the Asterias Butterfly ; but the 
smaller oneg, deposit several hundred eggs in one larva, as 
we have seen in the potato-worm, from whose skin hun- 
dreds of small ichneumons creep out, and immediately trans- 
