Multiple Hooks perm

Hello !

In case of Multiple content type in the same module,

I wrote my hook node info like this

function example_node_info() {
 return array(
  'ex1' => array(
	'name' => t('Demande de ex1'),
	'module' => 'ex1',
	'description' => t('Une demande de ex1.'),
	'has_title' => FALSE,
	'has_body' => FALSE,
  ),
  'ex2' => array(
	'name' => t('Demande ex2'),
	'module' => 'ex2',
	'description' => t('Une demande de ex2.'),
	'has_title' => FALSE,
	'has_body' => FALSE,
  ),
 );
}

Is it possible to define two perm's hooks like this :

/**
* Implements hook_perm()
*/
function ex1_perm() {
 return array(
  'create ex1',
  'edit ex1',
  'delete ex1',
 );
}
function ex2_perm() {
 return array(
  'create ex2',
  'edit ex2',
  'delete ex2',
 );
}

Because i can't see the permissions in the permissions' page...

Thanks for your help...