There are two hypotheses about the origin of mitochondria&colon; endosymbiotic and autogenous. Both stages will also use autogenous pressurization. Lead burning is an autogenous welding process. Some are characteristically autogenous and avoid filler. These are generally referred to as "autogenous" impact mills. It is not possible to autogenous weld HY-80 due to the formation of untempered martensite. The hemolymph toxins originate from autogenous de novo biosynthesis by the Chrysomelina beetle. The broad option of donor-sites makes practically all patients candidates for autogenous perforator flap reconstruction. The rocket will not use helium for pressure but will use autogenous pressurization. Other materials available xenografts (tissue donor from another species) and autogenous bone. In autogenous pressurization, a small amount of propellant is heated until it turns to gas. No filler rod is required, the sheets form their own filler (autogenous welding). Autogenous healing is the natural ability of cementitious materials to repair cracks. Most welding processes may be either autogenous, or may use additional filler. SAG mills are autogenous mills that also use grinding balls like a ball mill.