IJ2 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 the same. 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,^,^), 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 

 a retreat. 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 theirfather upon receiving them from the delighted 

 children. 



