Surcingle behind the withers. When used with a saddle, the surcingle runs over the seat near the pommel. A surcingle is also used over the top of certain types of pack saddle and pack to keep the pack bags and swag in place. A surcingle is usually used with a pad, and fit to the horse's back as carefully as a saddle would be. It is tightened enough to prevent slipping, more when used with a saddle and rider, less when used for ground training. Surcingle A surcingle is a strap made of leather or leather-like synthetic materials such as nylon
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