Reflection on Unity class

Hi, I am working on developer tool, I would like to call method from console in runtime like this: className.methodName param_1 param_2 For now it works, but it only can found method in my class, if I try find Unity class (for instance Application.LoadLevel()) it returns null. The code is:

 Type CheckInAllAssemblies(string typeName)
     {
         Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();
         Type type = null;
         foreach(var a in assemblies)
         {
             type = a.GetType(typeName);
             if(type != null)
                 return type;
         }
         return null;
     }

I also have found that this would return null as well:

         Type type = typeof(Debug).Assembly.GetType("Debug");