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涡虫咽藏在口后咽囊中,伸出取食时不易观察。有几种观察法曾被报道过,如:凹玻反置、培养皿投食上举等,但因涡虫取食时咽并不是完全伸出,加之食物的遮挡和投食后水体变浑,实验过程中怕震动等原因,实验观察效果也不理想,而且费时。笔者为了解决这一问题,经过反复试验,终于找到了一种用直流电电击涡虫来观察其伸出的咽的办法。此法十分方便有效,并同时可供几人肉眼观察,应用到实验教学中,学生们都非常感兴趣。实验步骤如下:
Worm worm hiding in the mouth of the pharyngeal capsule, sticking out when not easy to observe. There are several observations have been reported, such as: concave glass inverted, petri dish feeding on the move, but because of planarians pharyngeal feeding is not fully extended, in addition to the food shelter and feeding muddy water body , Fear of vibration during the experiment and other reasons, the experimental observation results are not ideal, but time-consuming. The author in order to solve this problem, after repeated tests, finally found a way to use DC electric beaters to observe its extended pharynx approach. This method is very convenient and effective, and at the same time available for a few naked eye observation, applied to experimental teaching, the students are very interested. The experimental steps are as follows: