strange memory occupier of allocatable array in custom type in Fortran

I wanna create an allocatable array in custom type as follows:

1. type cell
2.    integer(4) :: fn
3.    integer(4), dimension(:), allocatable :: nd
4. end type cell
5. type(cell), dimension(:), allocatable :: elem
6. allocate(elem(10000))

There is memory occupier ten times more than 10000*4 Bytes before allocating array nd, why?

I thought a custom type might not contains any uncertain array, and modified the code as follows:

1. type cell
2.    integer(4) :: fn
3.    integer(4), pointer :: nd(:)
4. end type cell
5. type(cell), dimension(:), allocatable :: elem
6. allocate(elem(10000))
7. do i=1,10000
8.    elem(i)%nd=>cnode(j:j+7)
9. end do

 where cnode is a target array. The same situation happens, i.g. the memory occupier is  ten times

more than (10000*4+10000*8*4), and why? What should I do to change this?