I have chosen two species of toad as my models.  Amphibians are excellent models for endocrine disruptor study because they have relatively short larval period and allow for multigenerational studies.  Not only do these species of toad inhabit atrazine-usage areas, but their risk for exposure is heightened by the ability for contaminants to cross their permeable skin.  The oak toad is native to Florida.  It is the smallest toad in North America