Slide showing four diagrams of larva of Bombinator which have had same operation as in Fig. 35. Slide shows four diagrams of larva of Bombinator which have had same operation as in Fig. 35. Diagrams are labelled 'a' - 'h'. The diagrams 'a','c', 'e' and 'g' are tinted blue. Title below image reads 'Fig. 38. a - h. The same operation as in Fig. 35 larvae of Bombinator. On the right side the normal optic cups with lenses; on the left side optic cups, the material of which had been diminished in varied degree; their lenses are diminished in size to the same extent. (After Spemann, 1912a).' Late 19th to early 20th century