Rate of growth in the regenerating tail is controlled by a variety of factors, such as age, condition, and activity of the individual, and site of the fracture. A break occurring early in the skink's lifetime results in regeneration more complete than occurs in an adult sustaining the same type of injury. The regenerated tail eventually may be longer and thicker than the lost part if the lizard is young and still growing. But the regenerated tail is never so long as the original one would have been. Regeneration is most extensive in those tails broken near the base. The farther from the base the break occurs the shorter is the part regenerated. As a result, tails that have had time to regenerate do not differ greatly in total length regardless of where the break occurred. However, the nearer the break is to the base, the shorter is the total tail-length after regeneration (Figures 19 and 20). If only the tip of the tail is lost, regeneration may not occur. In the skinks examined that had regenerated tails the proportions varied over a wide range. Presumably, in many, growth of the regenerated portion was still incomplete. [Illustration: FIG. 20. Diagrams showing typical extent of tail regeneration in skinks having tails broken at different points, × approximately 2/3. Original parts of the tails are at the right.] Table 14. Records of Regeneration of the Tail in Individual Skinks Marked and Recaptured. =================+==================+==========+======================== | |Snout-vent| Age and Sex | Date |length | Tail length | |in mm. | in mm. -----------------+------------------+----------+------------------------ No. 1. |June 1, 1951| 73 | 38 (newly broken) Adult male |June 26, 1951| 73 | 38 + 14 |August 17, 1951| 76 | 40 + 45 |April 29, 1952| 76 | 40 + 45 | | | No. 2. |May 28, 1949| 51 | 46 (newly broken) Immature |October 15, 1949| 69 | 51 + 21 | | | No. 3. |June 11, 1950| 49 | 49 (newly broken) Immature |September 2, 1950| 63 | 63 + 31 | | | No. 4. |August 10, 1950| 62-1/2 | 60 (newly broken) Immature female|June 14, 1951| 68 | 62 + 17 | | | No. 5. |August 14, 1950| 67-1/2 | 77 + 4-1/2 Adult male |September 3, 1950| 68-1/2 | 77 + 6-1/2 |April 27, 1951| 69 | 78 + 9 | | | No. 6. |April 7, 1950| 67 | 38 (newly broken; Adult male | | | separated end 66)