Let $\{Z_n\}$ be a branching process whose offspring distributions vary with $n$. It is shown that the sequence $\{\max_{i>0}P(Z_n=i)\}$ has a limit. Denote this limit by $M$. It turns out that $M$ is positive only if the offspring variables rapidly approach constants. Let $\{c_n\}$ be a sequence of constants and $W_n=Z_n/c_n$. It will be proven that $M=0$ is necessary and sufficient for the limit distribution functions of all convergent $\{W_n\}$ to be continuous on $(0,\infty)$. If $M>0$ there is, up to an equivalence, only one sequence $\{c_n\}$ such that $\{W_n\}$ has a limit distribution with jump points in $(0,\infty)$. Necessary and sufficient conditions for continuity of limit distributions are derived in terms of the offspring distributions of $\{Z_n\}$.