Table 3: Products mentioned in the text.

Extren: fiberglass-resign composite sheet, Strongwell Pultruded Products, Bristol, VA.
Fluon: frictionless coating solution, Northeast Chemical Co., Woonsocket, RI.
Heating pad: 4 watt reptile heating pad, Zoo Med Laboratories, San Luis Obispo, CA.
Hydrostone: gypsum cement, United States Gypsum, Chicago, IL.
Mortar color: concentrated dye, manufactured by Solomon Grind-Chem. Service Inc., Springfield, IL.
Plastic vials: clear styrene tubes with white snap-caps, BioQuip Products, Rancho Dominguez, CA.
Plastic boxes: clear containers with friction fitting lids, Tri-State Molded Plastics, Inc., Dixon. KY.
Vanderzant Vitamin Mix: powdered multi-vitamins, MP (formerly ICN) Biomedicals.
Wesson Salt Mineral Mix: powdered mineral salts, MP (formerly ICN) Biomedicals.
3-in-One Household Oil: light lubricant, Boyle-Midway Inc., New York, NY.