<?php

class Log
{
	public $tree;
	public $height;
	public $health;
	public $image;
	public $comment;
	
	function __construct($tre, $hei, $hea, $img, $com)
	{
		$this->tree = $tre;
		$this->height = $hei;
		$this->health = $hea;
		$this->image = $img;
		$this->comment = $com;
	}
}

?>

<?php

class Log
{
	public $tree;
	public $height;
	public $health;
	public $image;
	public $comment;
	
	function __construct($tre, $hei, $hea, $img, $com)
	{
		$tree = $tre;
		$height = $hei;
		$health = $hea;
		$image = $img;
		$comment = $com;
	}
}

?>

--- 
+++ 
@@ -10,11 +10,11 @@
 	
 	function __construct($tre, $hei, $hea, $img, $com)
 	{
-		$tree = $tre;
-		$height = $hei;
-		$health = $hea;
-		$image = $img;
-		$comment = $com;
+		$this->tree = $tre;
+		$this->height = $hei;
+		$this->health = $hea;
+		$this->image = $img;
+		$this->comment = $com;
 	}
 }
 
Update self reference in constructor