Null reference exception object reference not set in an instance of an object

I have 2 scripts one is a raycast script and one is a health script my error comes in on the raycast script on the code where i fire a raycast and access the void apply damage.

Health

 public class HealthBear : MonoBehaviour {
 
 
     public int health = 200;
     private bool isDead = false;
     public GameObject animal;
     // Use this for initialization
     void Start () 
     {
     
     }
     
     // Update is called once per frame
     void Update () 
     {
         
     }
     public void ApplyDamage (int amount)
     {
         if (isDead)
             return;
 
 
         health -= amount;
     
         if (health <= 0) 
         {
             Death ();
         }
     }
 
     public void Death ()
     {
         isDead = true;
 
         Destroy (animal, 3f);
     }
 }

Raycast

 using UnityEngine;
 using System.Collections;
 
 public class Raycast : MonoBehaviour 
 {
     public float range;
 
     private RaycastHit hit;
 
     private Transform myTransform;
 
     public float nextFire;
 
     public float fireRate = 0.3f;
 
     public HealthBear healthBear;
 
     public int damage;
 
 
     void Start ()
     {
         SetInitialreferences ();
 
 
     }
 
 
     void SetInitialreferences ()
     {
         myTransform = transform;
     }
 
     void FixedUpdate ()
     {
         CheckForInput ();
     
     }
 
 
     void CheckForInput ()
     {
         if (Input.GetButton("Fire1") && Time.time>nextFire) 
         {
             Debug.DrawRay (myTransform.TransformPoint(0,0,1), myTransform.forward, Color.red, 3);
             if(Physics.Raycast(myTransform.position, myTransform.forward, out hit, range))
             {
                 Debug.Log (hit.transform.name);
                 healthBear.ApplyDamage (damage);
             
             }
             nextFire = Time.time+fireRate;
 
         
         
         }
 
     }
 
     public void ApplyDamage (float damage)
     {
         
     }
 
 
 }