It is pointed out that in the variable x = 1 − tanh ( J kT ) , low temperature Ising model series converge up to the physical singularity. The low temperature susceptibility series in x for a s.c. Ising lattice is analysed and it is suggested that the exponent γ′ = 21 16 rather than 5 4 , the value implied by scaling and homogeneity arguments.