USEFUL AND NOXIOUS ANIMALS 21 



crabs). Some are quite extensively used as fertilizers (horseshoe crabs). 

 The mollusks, aside from importance to other animals, give us our pearls, 

 pearl buttons, shell work of all kinds (31), fertilizers, important food, ink, 

 cuttlebone, etc. (32). 



The insects are of such importance that nearly every state and 

 civilized country maintains an expensive staff of trained men whose 

 business it is to advise the public in regard to their treatment and to 

 investigate the relations of insects to industry. Their ravages or fear 

 of the same are the basis of some of the speculation which enriches some 

 and pauperizes other speculators in the necessities of human life. Aside 

 from this we have the numerous products from insects — tincture of 

 cantharides, honey, wax, lac (33), carmine (34), and cochineal. Many 

 are used as human food in the tropics (locusts, water-bugs, flies, larvae 

 of the palm weevil, etc.) . Some few, such as the scorpions, are poisonous. 

 Many diseases are known to be carried from person to person by insects 

 and arachnids (cholera, yellow fever, malaria, sleeping sickness, typhoid, 

 typhus, bubonic plague, mountain fever, perhaps leprosy) as well as a 

 great host of larger parasites. 



We turn now to the vertebrates, which are familiar and their uses 

 quite well known. From this group we get our leather, furs, animal 

 oils (snake oil, fish oil, turtle oil, lard, whale oil, skunk oil, woodchuck 

 oil, neatsfoot oil), all of which have recognition in the markets and some 

 of which have peculiar properties which adapt them to particular pur- 

 poses (32). Glue, gelatin, bone meal, fertilizers, bone black, etc., are 

 extensively used in industries; meats, dairy products, furs, leather, etc., 

 are necessities. 



We must not, however, fail to call attention to animals as the basis 

 for nearly all experimental study of life processes, of heredity, of behavior 

 and psychology, of diseases and their cure and prevention. The public 

 should disabuse itself of the idea that biological investigators are wasting 

 their time on bugs, for lower animals are the only material upon which 

 the problems of our race can be solved, and until we are prepared to sub- 

 mit ourselves to be used in the solution of our own problems, biologists 

 will be compelled to use lower animals as material. 



