PHP构造函数 在一个类中调用另一类的构造函数怎么会出错？？？？？？？

<?PHP
class Student
{
private $Name;
private $Age;
private $Sex;
function __construct($name,$age,$sex)
{
$this->Name = $name;
$this->Age = $age;
$this->Sex = $sex;
echo("被调用构造函数");
}

class person
{
function __construct()
{
Student::__construct("张",24,"男");
echo("调用构造函数");
}
}

$St = new person();
?>

运行后 怎么会有错？？？
错误信息如下：
Fatal error: Non-static method Student::__construct() cannot
be called statically, assuming $this from incompatible context
in E:\www\mytext\opp01.php on line 136

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