In the Following Code, Identify the First and Second Base

In the following code, identify the first and second base case, and evaluate whether this code would have an efficient running time.
1 public static int recursiveBinarySearch
2 ( int [ ] arr, int key, int start, int end )
3 {
4 if ( start <= end )
5 {
6 int middle = ( start + end ) / 2;
7 if ( arr[middle] == key )
8 return middle;
9 else if ( arr[middle] > key )
10 return recursiveBinarySearch( arr, key, start, middle - 1 );
12 else
13 return recursiveBinarySearch( arr, key, middle + 1, end );
14 }
15 else
16 return -1;
17 }