Relations between magnetism and morphology in submonolayer films of Fe(110) on W(110) were studied using spin polarized electron diffraction and scanning tunneling microscopy. Films prepared at 600 K form monolayer stripes along with the W steps; they are ferromagnetic with T_c slowly decreasing from 225 K near theta=1 to 180 K near theta=0.1. The decrease scales with 1 / theta. Films prepared at 300 K nucleate by islands which start to coalesce near theta =0.6. For theta <= 0.58, they are superparamagnetic at T >= 115 K. In a narrow theta range of only 2%, magnetic percolation occurs, resulting in ferromagnetism with T_c >= 190 K for theta >= 0.60.