he·ma·tol·o·gy 
(hē′mə-tŏlə-jē)
(hē′mə-tŏlə-jē)n.
The branch of medicine that deals with the diagnosis and treatment of diseases of the blood and bone marrow.
he′ma·to·logic (-tə-lŏjĭk), he′ma·to·logi·cal adj.
he′ma·to·logi·cal·ly adv.
he′ma·tolo·gist n.