Abstract
Ether resistant strain (Eth-29) and one of the sensitive strains (bw; st; svn) which were assessed by mortalities, were used to determine median effective doses (ED50) of halothane and chloroform. It was demonstrated that the Eth-29 strain was resistant and the bw; st; svn strain was sensitive to both of halothane and chloroform anesthesia. Reciprocal crosses between the two strains suggested that the resistance to halothane anesthesia was a sex-linked recessive trait and that the resistance to chloroform anesthesia was an autosomal incompletely dominant or a polygenic trait. Maternal effects may not be negligible in both of the resistant traits.
