雄变雌的实验若干年前,我国胚胎学家张致一先生会做过一个有趣的实验:他用一种雌性激素处理一种蛙类(一种非洲蟾蜍)的雄性蝌蚪,经过处理的全部蝌蚪都长成雌蛙。这些雌蛙都会产卵;卵受精后发育成蝌蚪,全部蝌蚪都发育成雄蛙。连续几次处理,结果一样。这个实验的结果告诉我们,雄可以变雌,例如雄性蝌蚪吸收了雌性激素就发育成雌蛙。现在要问:性别为什么可以转变?决定性别的因素是什么?上述实验中起初用雌性激素处理的全部雄性蝌蚪为什么都发育成雌蛙?这些雌蛙所产生的全部蝌蚪为什么都发育成雄蛙?性染色体决定雌雄的因素相当复杂,有遗传的因素,也有环境的因素。两 Experiments with male fertilization Several years ago, our embryologist Mr. Zhang Zhiyi did an interesting experiment: he used an estrogen to treat male fleas of a frog (a type of African salamander) and processed all of them. All grow into female frogs. These female frogs lay eggs; the eggs develop into crickets after fertilization and all crickets develop into male frogs. After several consecutive treatments, the result is the same. The results of this experiment tell us that males can become females. For example, males develop female frogs by absorbing female hormones. Now we have to ask: Why can sex be changed? What are the factors that determine gender? Why did all the males that were initially treated with estrogen in the above experiments develop into female frogs? Why do all the fleas produced by these female frogs develop into male frogs? The factors that determine the male and female chromosomes are quite complex, with both genetic and environmental factors. Two