Systematic Course. 17 
way back to the original nest or starts a fresh nest for 
herself. Her abdomen gradually grows’ by distention of 
the membrane between the chitinous plates, until she 
becomes like a sausage, two or three inches long, with a 
minute head and thorax atone end. Queens in several 
stages of development may sometimes be found in a single 
nest. 
White-ants attack dead wood, paper, cloth and other substances. 
They never willingly expose themselves to day-light but work in 
earthen galleries, wich they build over themselves as they advance. 
They sometimes attack young sugarcane, also plants in nurseries, 
ut can be removed by copious watering and by opening up the earth 
around the stem so as to admit light and air. They also cover trees 
with their earthen galleries and feed on the outer portion of the bark. 
When the trees are healthy, however, little or no damage is done. 
White-ants will not attack good teak or other really hard wood even 
when dry. About the most effective insecticide for use against them is 
kerosine oil, which is peculiarly distasteful to insect life of all kinds, 
but they are susceptible to almost every kind of insect poison, though 
the use of these substances is only practicable in some cases, It should 
be noticed that white-ants do good service in forests by converting 
fallen branches into soil. The students should examine the specimens 
in the School Museum. 
Libeilulide (Dragon-flies).—These insects are of no special import- 
ance, and are only noticed as they are excessively common and con- 
spicuous. They are totally different in appearance from the other 
Orthoptera, their most characteristic features being their large mem- 
branous wings, supported by a fine network of veins, and their short, 
slender, pointed antenne. Unlike the groups noticed above, their 
larve live in water. Dragon-flies feed on insects both in their larval 
and winged stages. The larva has the labium enormously developed 
for catching its prey, and breathes water by means of a modification 
of the trachee in the posterior of the body. Thee students should 
sketch a representative specimen in the Museum. If possible they 
should also examine the larva. 
H}.—Rhynchota. 
The Rhynchota comprise a lJarge number of very distinct forms. 
They may be defined as insects furnished with a jointed proboscis, no 
pupal stage being present. ‘he Jarve are little creatures much like 
their parents, but without wings, They are active throughout their 
entire existence. The jointed proboscis has arisen asa modification of 
c 
