R plot is missing a line that I think it should have

Question

When I try this:

fitBlack=dim(501)
fitWhite=dim(501)
ag=dim(501)
for (i in 1:501) {
ag[i]=(99+i)/100
fitBlack[i]=exp(m1$coef[1]+ag[i]*m1$coef[3])/(1+exp(m1$coef[1