Professor T. C. Tung ( Fig. 1) was a prominent experimental embryologist in China. He was born in Jin County, Zhejiang Province, China in 1902. After he obtained his Bachelor’s degree from the Department of Biology, Fudan University, Shanghai in 1927, he was appointed as a teaching assistant in that department until he moved to Belgium in 1930. He studied as a graduate student in Professors A. Brachet and A. M. Dalcq’s laboratory at the Universite Libre de Bruxelles, Belgium and obtained his Doctor of Science degree there in 1934. During that period, he made two short working visits to the Institute of Marine Biology in France and took one training course at Cambridge University (UK). In 1934, he was invited to return to China as a Full Professor to teach at several Chinese universities, (Shandong University in Qingdao, Shandong Province; the National University in Nanjing; and Fudan University in Shanghai). He spent 1 year at Yale University (USA) between 1948 and 1949 as an invited scientist in a joint research project and finally returned to China in 1949. He was Chairman of the Department of Zoology, Shandong University in Qingdao (1949~1952), Vice‐President of Shandong University (1952~1960), Director of the Marine Biological Institute, the Chinese Academy of Sciences (CAS) in Qingdao (1949~1958), Director of the Institute of Oceanology (CAS) in Qingdao (1959~1966), Director of the Institute of Zoology (CAS) in Beijing (1960–1962), member of CAS since 1955, Vice‐Chairman of the Biological and Geographical Division of CAS (1955~1958), Chairman of the Biological Division of CAS (1959~1979) and Vice‐President of CAS in Beijing (1978–1979). In spite of his administrative duties, he spent most of his life conducting bench work in his laboratories at the Institutes of Oceanology and Zoology, CAS, respectively, until he passed away in March 1979. Professor Tung’s main research interest was with classic experimental studies on the determination of the egg axis and symmetry planes of fertilized eggs, early differentiation and organizing substances of egg cytoplasm, induction between embryonic cells and cytoplasm in embryogenesis, immunological studies on nuclear transplanted eggs, and cell fusion etc., in several types of animals. He conducted his experiments on a number of invertebrates (ascidians and Amphioxus) and vertebrates (fish and amphibians) by means of very skilful microsurgical operations and the nuclear transplantation method. Among these topics, his studies on the organization and developmental potency of Amphioxus eggs were unique. His important contribution to this research field involved not only establishing a practical method for collecting and using this rare animal for experimental purposes, but also clarifying controversy about the nature and early development of its eggs. He also provided conclusive evidence to determine its evolutionary position between invertebrates and vertebrates.The present article briefly reviews the main results obtained by Professor Tung and his colleagues on Amphioxus. ...

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Isolated two dorsal animal blastomeres of 8-cell-stage Xenopus embryos differentiated in about 24% of the cases into mesodermal structures, while the two ventral animal ones formed exclusively atypical epidermis. Of special interest is the fact that most of the dorsal animal blastomeres without mesodermal structures, differentiated into atypical epidermis with large parts of cement gland. Cement glands could not be detected in the derivatives of the ventral animal blastomeres. In earlier concepts it has been suggested that the animal hemisphere of the amphibian egg is an uncommitted area, which receives its instructions for further determination and differentiation from the vegetal part of the embryo. However, the results, shown in this paper, support the view that the developmental determinants are distributed in distinct gradients already in the early cleavage stages. Although the highest concentrations of these putative determinants are located in the dorsal vegetal area (Melton, 1995) and the dorsal marginal zone, lower concentrations of these substances are thought to be present in the animal part, especially in the dorsal animal hemisphere of the egg and the early embryo. Our results indicate that dorsal animal blastomeres of early cleavage stage embryos possess the capacity to form mesodermal derivatives after their separation from the vegetal hemisphere.