Slide showing tinted microscopic image of the 'Anterior heart region of the larva of Triton Taeniatus.' Slide shows tinted microscopic image of the 'Anterior heart region of the larva of Triton Taeniatus' (newt). Part of the image is tinted red. Title below image reads: 'Fig. 50. Anterior heart region of the larva of Triton Taeniatus. A lens has been induced by a piece of boiled heart of Salamandra which had been implanted into the blastocoele in an advanced stage of gastrulation. (after Holtfreter, 1934b).' Late 19th to early 20th Century