blastogenesis /blas′tōjen″əsis/ [Gk, blastos + genein, to produce] , 1. asexual reproduction by budding. 2. the transmission of hereditary characteristics by the germ plasm. Compare pangenesis. 3. the early development of an embryo during cleavage and formation of the germ layers. 4. the process of transforming small lymphocytes in tissue culture into large, blastlike cells by exposure to phytohemagglutinin or other substances, often for the purpose of inducing mitosis. −blastogenetic, adj.