The Collaborative International Dictionary of English v.0.48:

Haematogenesis \H[ae]m`a*to*gen"e*sis\
   (h[e^]m`[.a]*t[-o]*j[e^]n"[-e]*s[i^]s or h[=e]`m[.a]*t[-o]-),
   n. [H[ae]mato- + genesis.] (Physiol.)
   (a) The origin and development of blood.
   (b) The transformation of venous into arterial blood by
       respiration; hematosis.
       [1913 Webster]

WordNet (r) 3.0 (2006):

haematogenesis
    n 1: the formation of blood cells in the living body (especially
         in the bone marrow) [syn: hematopoiesis,
         haematopoiesis, hemopoiesis, haemopoiesis,
         hemogenesis, haemogenesis, hematogenesis,
         haematogenesis, sanguification]