Poisonous Animals op the Dkskrt ^75 



sleep out unprotected, that is a question for each individual to 

 settle for himself. 



INVERTEBRATES 



The remaining animals to be treated here all belong to a quite 

 different group, the Arthropoda, or "jointed-foot" animals, having a 

 characteristic horny outer shell or exoskeleton, rather than a bony 

 skeleton within the body : and those of this immense group which 

 interest us here are the insects and their relatives the spiders, scor- 

 pions, centipedes, etc. 



It is a peculiar fact that while fear of certain forms of insects 

 is much exaggerated or entirely unfounded, yet certain other in- 

 sects which actually cause thousands of cases of illness and death 

 not only do not cause general alarm, but it is well-nigh impossible 

 to arouse some classes of the population to their importance. These, 

 are the insects definitely proven to carry diseases of man. Such 

 common insects as house-flies, carrying typhoid fever and other 

 diseases; body-lice carrying the dread .typhus fever; malarial 

 mosquitoes, and the yellow fever mosquito, are examples of these. 

 Yet the less educated people can hardly be forced to give attention 

 or thought to these deadly, but non-poisonous, insects ; while the 

 harmless "campamocha" and "Child-of-the-Desert" are greatly 

 feared. This bulletin is not to deal with the disease carriers, how- 

 ever, important as they are, for much more of both general and 

 particular information is available concerning them than concern- 

 ing other, actually less important, but poisonous or feared kinds of 

 this region. 



INSECTS 



First to be mentioned among poisonous insects are bees, wasps, 

 and ants, and they are discussed in part for purposes of illustration 

 and comparison, since they are familiar to every one. All bees and 

 wasps, and many ants of the Southwest, have stings with which a 

 definite poison is injected into the wound made. All ants, whether 

 stinging or not, attack by biting. The bite is only a pinch with the 

 jaws and is in itself non-poisonous ; but even the stingless ones 

 possess the usual poison glands, and these are said to bring the 

 tip of the abdomen forward and spray poison into the wound made 

 by biting. The sting, in so far as we humans are concerned, is only 

 a weapon of defense, never of offense, and we need not fear the bee 

 or wasp visitor so long as we attend quietly to our own affairs and 



