The basophils are probably like mast cells of connective tissue. They release heparin, histamine and serotonin. Their nucleus is usually three lobed and their granules take basic stain strongly.
Monocytes are largest of all types of leucocytes. Their mucleus is bean-shaped. They are motile and phagocytic in nature. They engulf bacteria and cellular debris. Generally, they will change into macrophages after entering tissue spaces. Eosinophils have two-lobed nucleus. They are non-phagocytic and help in dissolving blood clot. Their number increases in people with allergic conditions such as asthma or hay fever. Neutrophils are most numerous of all leucocytes. They eat harmful germs and are therefore, phagocytic in nature. Their nucleus is many lobed and stain weakly with both acid and basic stains.