The water content of these tissues is either inside the cells (intracellular fluid) or surrounding these (extra cellular fluid). Since the lowest concentration of solutes is found in the extra cellular fluids, the first ice crystals are formed there. During a slow freezing, there will be time for the cell to lose water by diffusion and the water will freeze on the surface of the crystals already formed. As the cells keep losing water, the cell shrinks more and more until it collapses