ONE more question about Pointer math --> 3dfxMM

#include <stdlib.h>

typedef struct{
  int num;
  int val;
}blah;

typedef struct{
  int nonsense;  
  blah * blahAr;
}fool;

void printBig(fool * start, fool * end);
void printOne(fool T); 

int main()
{
   fool * big=NULL;
   fool * bigTail; 
   fool * bigptr;
   int i=0,j=0; 
   int bigsize=0;
   int onesize;
   blah temp; 

   fool foolish;
   foolish.blahAr = malloc(sizeof(blah)*2);
   onesize = sizeof(blah)*2 + sizeof(int);

   while(i<3)
   {
      temp.num = i+15;
      temp.val = i+15;
      foolish.nonsense=i;

      for(j=0; j<2; j++)
     {
         temp.num++;
         temp.val++;
         foolish.blahAr[j] = temp;
     }

     bigsize += onesize; //recalculate size of big
     big = realloc(big, bigsize); 
     bigTail = big + bigsize/onesize - 1;  
     memcpy(bigTail, &foolish, onesize); 
     bigTail++; //adjust tail
     i++; 
     printBig(big, bigTail); //print list
  }

   printBig(big, bigTail); //print list
   return 0;
}

void printBig(fool * start, fool * end, int size)
{
   int i;
   fool * head = start;
   fool * tail = end;

   printf("{ \n");
   while(start!=end)
  {
     printOne(*start);
     start++;
  }

   printf(" }\n"); 
}

void printOne(fool T)
{
    int i=0;
    printf("[ ");
    for(i=0;i<2;i++)
       printf("(%d, %d) ", T.blahAr[i].num, T.blahAr[i].val);
    printf(" ]");
}