title: Antibody Formation in Embryos.
abstract: The production of agglutinins to Salmonella typhi was studied in the opossum embryo in the period immediately before and after the development of thymic and lymph node lymphoid tissue. Antibody was found only in embryos older than 8 days which corresponds to an 8- to 10-week human embryo in terms of organogenesis and is the earliest stage at which antibody production has been recorded.
authors.forename: M F
authors.initials: MF
authors.lastname: La Via
authors.forename: D T
authors.initials: DT
authors.lastname: Rowlands
authors.forename: M
authors.initials: M
authors.lastname: Block