Table 1.

Results of a logistic regression analysis in which the response variable was survival, entered as a two-state variable; change in gamma globulin level, premanipulation tail length, and age were the independent regressors; and three dummy variables accounted for the pairwise comparisons between the group of males whose tails were not manipulated (Control I) and the groups of males whose tails were cut and reglued (Control II), shortened, or elongated, respectively.

Predictor	χ2	P
Control I vs. Control II	0.22	NS
Control I vs. shortened	0.00	NS
Control I vs. elongated	0.01	NS
Change of gamma globulins	7.59	0.006
Premanipulation tail length	7.30	0.007
Age	0.04	NS

NS, not significant.