Do Generics not inherit initializers?

Four classes, first two normal, Two inherits from One, Two inherits One's initializers as expected.

Second two are generic, Four<T> inherits from Three<T>, but everything else is the same. However Four doesn't inherit Three's initializer.

Is that a bug or have I missed yet something else in the Swift book?

public class One
{
  public var value : Int
  public init( value : Int )
  {
  self.value = value
  }
}
public class Two : One
{
  public func foo()
  {
  print( "value is \(value)" )
  }
}
public class Three<T>
{
  public var value : T
  public init( value : T )
  {
  self.value = value
  }
}
public class Four<T> : Three<T>
{
  public func foo()
  {
  print( "value is \(value)" )
  }
}
let x = Two( value : 123 )             // *** WORKS ****, Two inherits One's init(value:) method
x.foo()
let y = Four<Int>( value : 123 )      // Four<Int>' cannot be constructed because it has no accessible initializers
y.foo()