[C# 4.0 in a Nutshell, pg 83]
If a subclass omits the base keyword from the contructor, do any of the base class contstructors get called?
public Subclass (int x) instead of:
public Subclass (int x) : base (x)
Yes, the parameterless contructor in the base class gets implicitly called. If this is missing from the base class, the subclass is required to use the : base(...) construct.