Bronc riding toward the rigging handle, spurring at each jump in rhythm with the motion of the horse. Bareback bronc riding began to develop as a professional rodeo sporting event around 1900. The riding equipment used during that era varied. In some cases, the rider simply held onto the horse's mane, called a mane-hold. Others held a loose or twisted rope tied around the horse's girth, and other methods involved using multiple handhold leather riggings based on a surcingle. In the early 1920s, when the old rodeo rules allowing two handed riding were being phased out and replaced with the newer rule
Animal testing on invertebrates Animal testing on invertebrates Most animal testing involves invertebrates, especially "Drosophila melanogaster", a fruit fly, and "Caenorhabditis elegans", a nematode. These animals offer scientists many advantages over vertebrates, including their short life cycle, simple anatomy and the ease with which large numbers of individuals may be studied. Invertebrates are often cost-effective, as thousands of flies or nematodes can be housed in a single room. With the exception of some cephalopods, invertebrate species are not protected under most animal research legislation, and therefore the total number of invertebrates used remains unknown. Research on invertebrates is the foundation for current understanding of