Slide showing microscopic photograph of 'Triton Taeniatus, with an almost normal secondary embryo on the ventral side, in inverted orientation.' Slide shows black and white microscopic photograph of 'Triton Taeniatus, with an almost normal secondary embryo on the ventral side, in inverted orientation.' Title below image reads: 'Fig. 133, Triton Taeniatus, with an almost normal secondary embryo on the ventral side, in inverted orientation. The secondary embryo has been induced by a large piece of dorsal marginal zone of Triton alpestris which had been implanted into the blastocoele of a young gastrula. (After Holt-freter, 1933e.)' Late 19th to early 20th century