546 Charles Zeleny 
TABLE 17 
Cambarus bartoni. Nos. 2218-2267. Regeneration of the chele when both are removed at one time. 
Older crayfish. Molts 8-9, 9-10, and 10-11 
LENGTH OF REGENER- |SPECIFIC 
CATA- | | CEPHALO-THORACIC LENGTHS SPECIFIC 
INTER- ATING CHELAE AMOUNT 
LOGUE | ee Ot vei Tee Ser: 2 a ee RATE OF 
aoe MOLTS | VAL IN eee, | ier | p OF, RES |e 
| ah t TeYr- | 
BER Bae Saas ee ae Left | Right | / | “*®“"| eration 
| 8 OF we II fouee age ATION 
| 
al | | | | 
2222 8-9 | 27 10.9 | 11.9 5-4 | 5:5 5-45 | 0.50 0.019 
pp || =e) | 2 ge | siting I ayes! 5-0 5.05 | 0.48 0.022 
2233 | ro-4r | 30 T2t 13.6 | 6.8 | 6.6 6.7 0.55 | 0.018 
2240 8-9 20 TO 5 ey |e EE Onn lie von face 4.8) |pOxau 0.0205 
2258 g-10 | 25 ips) ||) ue} ce) | 5-9 | 6.0 5-95 | 0.50 | 0.020 
Average]|........ | 24.8] 10.7 | 11.67 | 12.55 | 13.6 | §5.46| 5.52]. 5.49 | ©.488| 0.020 
The average lengths of the regenerated chele when a single 
chela is removed is 5.36 mm. for the five available cases as com- 
pared with a regenerated length of 5.46 mm. for the right chela 
and 5.52 mm. for the left chela in individuals in which both 
chelz are removed. ‘The average specific amount of a regenerat- 
ing chela is 0.484 when it alone is removed and 0.488 when the 
other chela is removed at the same time. The average specific 
rate of a regenerating chela likewise is 0.017 when it alone 1 
removed and 0.020 when the other chela 1s removed at the same 
time. 
The advantage on the whole is evidently in favor of the regen- 
erating chelz in individuals with the greater injury. 
Second Regeneration 
The data for second regenerations are given in Tables 18 
and 19. 
The average length of a regenerating chela in the nine cases in 
which it alone is removed is 4.5 mm. and in the three cases in 
which both chelz are removed the averages are 5.1 mm. for the 
left chela and 5.1 mm. (?) for the right. 
The average specific amount for the lesser injury to the indi- 
vidual is 0.521 and for the greater injury 0.563. 
