The Journal of Experimental Zoölogy, 1919, Vol. 29 (Classic Reprint)

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Excerpt from The Journal of Experimental Zoölogy, 1919, Vol. 29 A layer Of paraffin blackened with carbon was put into a Syracuse watch-glass and in it were made six grooves, each sufficiently wide to admit an embryo lying ventral Side up. After the thyroid gland was removed the embryo was left in position for about an hour or until five other operations had been performed, the first then being removed to make room for the seventh. By that time the wound had sufficiently healed to permit handling with a pipette. Asepsis was found to be unneccessary. The operations were performed under a binocular microscope. A transverse incision was made with fine scissors through the ectoderm posterior to the oral plate, the ¿ap Of ectoderm covering the thyroid anlage was pulled caudally, the mesenchyma pushed laterally or removed, and the exposed anlage Of the thyroid was removed together with that portion Of the ventral wall Of the pharynx surrounding its proximal margin. The thyroid being Opaque is readily distinguished from the translucent mesenchyma. Care must be taken to avoid injury to the pericardium and heart. Usually the wound appeared to be healed in two or three hours. After the Operation (one to two hours) the salt solution was gradually diluted with tap-water. It was found that the em bryos were harmed by being left too long in the saline. Many sylvatica larvae were kept together in the same aquarium, but the Amblystoma larvae were isolated to prevent their eating one another's gills. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.