Effect of Age upon Regeneration 583 
TABLE 11 
Amblystoma jeffersonianum. Nos. 2172-2214. First regeneration. Older individuals. Regenera- 
tion period = 10 days (Fune 10 to Fune 20, 1907). Age at time of operation = 135 days 
| PART OF TOTAL | | SPECIFIC | SPECIFIC 
| | LENGTH OF | LENGTH OF 
CATALOGUE) TAIL LENGTH TAIL AMOUNT | RATE OF 
REMOVED | REGENER- | 
NUMBER | REMOVED | OF | LENGTH | | OF REGEN- | REGENER- 
| | TAIL | ATED TAIL 
(APPROX.) | ANIMALS | / | ERATION | ATION 
| | | | 
oh SO 
2175 whole, 50.4 24.2 20.0 3-7 } 0.38 0.018 
2181 whole 53-8 26.1 20.4 Aede lie On22 0.022 
2185 whole 54.1 27.9 2tat 3-0 0.14 0.014 
2193 whole 48.4 23.5 18.5 2.8 0.15 0.015 
2198 whole 53-2 fe Basar 21.0 Wnty | heey, 0.007 
2203 whole Sas On cle 26 21.3 4.0 0.19 0.019 
2207 whole 50.5 25.4 21.2 3.8 0.18 0.018 
2214 whole 49.0 (\2aat 20.2 4.3 0.21 0.021 
| Ei Lee 
| 
AVETARE i\2|stare oie! sical te RUG he) 2eab 20.5 BC Awe is OnTO7 0.0167 
2177 half | 56.2 28.7 1303 Nee} | 0.36 0.016 
2188 | half R40)  2yer 12.1 1.0(?)| 0.08 0.908 
2194 half | 49.8 | 23.4 11.0 2.2 0.20 0.020 
2205 half 47-4 DASA ip iif ere none 
2209 | half geet | 1226.6 10.5 1.6 0.14 0.014 
PETAR cics| ca'e Shas 5 Gls 51.9 aio) eee as 0.0145(-) 
