Hexapoda, or True Insects 
27 
Clarke’s column had been destroyed. The perivascular sheaths 
were crowded with small round cells and the meninges were con¬ 
gested. Some of the cells of the anterior horn were swollen and the 
nuclei eccentric; chromatolysis had occurred in many of them. 
As for treatment, Castellani and Chalmers (1910), recommend 
bathing the part well with a solution of ammonia (one in five, or one 
in ten). After bathing, apply a dressing of the same alkali or, if 
there is much swelling and redness, an ice-bag. If necessary, hypo¬ 
dermic injections of morphine may be given to relieve the pain. 
At a later period fomentations may be required to reduce the local 
inflammation. 
THE HEXAPODA OR TRUE INSECTS 
There are a number of Hexapoda, or true insects, which are, in 
one way or another, poisonous to man. These belong primarily 
to the orders Hemiptera, or true bugs; Lepidoptera, or butterflies 
and moths (larval forms); Diptera, or flies; Coleoptera, or beetles; 
and Hymenoptera, or ants, bees, and wasps. There are various ways 
in which they may be poisonous. 
1. Piercing or biting forms may inject an irritating or poisonous 
saliva into the wound caused by their mouth-parts. 
2. Stinging forms may inject a poison, from glands at the caudal 
end of the abdomen, into wounds produced by a specially modified 
ovipositer, the sting. 
3. Nettling properties may be possessed by the hairs of the insect. 
4. Vescicating, or poisonous blood plasma , or body fluids are 
known to exist in a large number of species and may, under excep¬ 
tional circumstances, affect man. 
For convenience of discussion, we shall consider poisonous insects 
under these various headings. In this, as in the preceding discussion, 
no attempt will be made to give an exhaustive list of the poisonous 
forms. Typical instances will be selected and these will be chosen 
largely from North American species. 
PIERCING OR BITING INSECTS POISONOUS TO MAN 
Hemiptera 
Several families of the true bugs include forms which, while 
normally inoffensive, are capable of inflicting painful wounds on man. 
In these, as in all of the Hemiptera, the mouth-parts are modified 
