Although the brown recluse has not yet been reported in Arizona, it may be expected at any time, according to Dr. Mont A. Cazier, professor of zoology at Arizona State University at Tempe. In the meantime, studies are being made of the several close relatives of _Loxosceles reclusa_ known to be present in the state. Among these is _L. unicolor_, first collected near Littlefield and Virgin Narrows in 1932. Equally poisonous with _reclusa_ is the similar _L. laeta_, also found in Arizona. Other members of the genus, _L. deserta_ and _L. arizonica_, have been known to live in Arizona and elsewhere in the Southwest for more than three decades, but no studies have been made of their venom. Dr. Willis J. Gertsch, world famous authority on spiders, believes that there may be as many as 20 species of _Loxosceles_ in the Southwest. Several reports by persons who have been bitten by spiders describe reactions similar to those caused by the bite of the brown recluse. According to Dr. Findley E. Russell, toxicology researcher of the University of Southern California Medical School, the “venom” injected by the brown spider is not really a toxin but a complete chemical that inhibits the normal action of infection-fighting antibodies in the human anatomy. Tarantulas (_Avicularia_ sp.) Known to naturalists as bird spiders, the large hairy members of the genera _Avicularia_, _Dugesiella_, and _Aphonopelma_ of the arid Southwest are commonly called tarantulas. [Illustration: _Tarantula_ (Photo by Marvin H. Frost Sr.)] This name originated in southern Italy where, centuries ago, according to a story, in the little town of Tarantum (now Taranto) there developed an epidemic of “tarentism” supposedly resulting from the bite of a large wolf spider (_Lycosa tarantula_). Victims were affected with melancholy, stupor, and an irresistible desire to dance. Presumably, the Neapolitan folk dance, Tarentella, came about as a result of an effort to develop a cure for tarentism. Early day immigrants brought to the western hemisphere both the unreasoning fear of spider bites and the name “tarantula,” which they applied to the large and fearsome-looking bird spider of the Southwest. Since that time this superstitious fear has become established among the uneducated and uninformed people of the southwestern United States, where the bird spiders are numerous. It has been spread and aggravated by prolific writers of western thrillers, published in the pulp-paper magazines. Fantastic tales in which the big spiders followed their victims, sprang upon them from distances of from 6 to 10 feet, and inflicted painful bites resulting in lingering, agonizing death have had wide circulation and have found a credulous audience.