72 Reproductive Organs in Insects. 
be appropriated by bees and conveyed to the hives. In 
those insects that suck their food, as bees, butterflies, moths, 
two-winged flies and bugs, the feces are liquid, while in case 
of solid food the excrement is nearly solid. 
SECRETORY ORGANS OF INSECTS. 
I have already spoken of the salivary glands, which Kirby 
describes as distinct from the true silk-secreting tubes, 
though Newport thinks them one and thesame. In many 
insects these seem absent. I have also spoken of the mucous 
glands, the urinary tubules, etc. Besides these, there are 
other secretions which serve for purposes of defense. In 
the queen and workers of bees, and in ants and wasps, the 
poison intruded with the sting is an example. This is se- 
creted by glands at the posterior of the abdomen, stored in 
sacs (Fig. 23, p, g'), and extruded through the sting as occa- 
sion requires. I know of no insects that poison while they 
bite, except it be mosquitos, gnats, etc., and in these cases 
no special secreting organ has been discovered. Perhaps 
the beak itself secretes an irritating substance. A few 
exceedingly beautiful caterpillars are covered with branch- 
ing spines, which sting about like a nettle. We have 
three such species. They are green, and of rare attraction 
so that to capture them is worth the slight inconvenience 
arising from their irritating punctures. Some insects, like 
bugs, secrete a disgusting fluid or gas which affords pro- 
tection, as by its stench it renders these filthy bugs so offen- 
sive that even a hungry bird or half-famished insect passes 
them by ‘on the other side. Some insects secrete a gas 
which is stored in a sac at the posterior end of the body, 
and shot forth with an explosion in case danger threatens; 
thus by noise and smoke it startles its enemy, which beats 
aretreat. I have heard the little bombardier beetle at such 
times, even at considerable distances. The frightful reports 
about the terrible horn of the tomato-worm larva are mere 
nonsense; a more harmless animal does not exist. My 
little boy of four years, and girl of only two, used to bring 
them to me last summer, and regard them as admiringly 
as would their father upon receiving them from the delighted 
children. : 
