看看这段程序，为什么这样的“继承”会出错？

abstract class Glyph {
  abstract void draw();
  Glyph() {
    System.out.println("Glyph() before draw()");
    draw();
    System.out.println("Glyph() after draw()");
  }
}

class RoundGlyph01 extends Glyph {
  int radius=0;
  String s;
  RoundGlyph01(int r,String s) {
   radius=r;
   this.s=s;
   System.out.println("RoundGlyph01.RoundGlyph(),radius="+radius+" "+s);
  }
  void draw() {
    System.out.println("RoundGlyph01.draw(),radius="+radius+" "+s);
  }
}

class RoundGlyph02 extends Glyph {
  int radius=0;
  String s;
  RoundGlyph02(int r,String s) {
   radius=r;
   this.s=s;
   System.out.println("RoundGlyph02.RoundGlyph(),radius="+radius+" "+s);
  }
  void draw() {
    System.out.println("RoundGlyph02.draw(),radius="+radius+" "+s);
  }
}

class RoundGlyph03 extends RoundGlyph01 {
  int radius=0;
  String s;
  RoundGlyph03(int r,String s) {
   radius=r;
   this.s=s;
   System.out.println("RoundGlyph03.RoundGlyph(),radius="+radius+" "+s);
  }
  void draw() {
    System.out.println("RoundGlyph03.draw(),radius="+radius+" "+s);
  }
}

public class PolyConstructors {
  public static void main(String[] args) {
    System.out.println("Creating object RoundDlyph01...");
    new RoundGlyph01(5,"String");
    System.out.println("**********************************************");
    System.out.println("Creating object RoundDlyph02...");
    new RoundGlyph02(5,"String");
    System.out.println("**********************************************");
    System.out.println("Creating object RoundDlyph03...");
    new RoundGlyph03(5,"String");
    System.out.println("**********************************************");
  }
}
 

编译结果：
PolyConstructors.java:40: cannot resolve symbol
symbol  : constructor RoundGlyph01 ()
location: class RoundGlyph01
  RoundGlyph03(int r,String s) {
                               ^
1 error

经过测试，如果我把RoundGlyph03 继承Glyph而非RoundGlyph01，一切正常，那么为什么继承RoundGlyph01就会出现如上错误呢？