Experiments were made with apparatus, largely of glass, specially designed to study the vertical movements of plankton animals under as natural conditions as possible at various depths in the sea. The animals were introduced in darkness into the apparatus which was kept covered with a black clothuntil it was lowered below the surface so that from the time they were caught, in the opaque tow-net bucket, to the time they were returned to the sea in the apparatus, they were never subjected to above-surface illumination. The experiments were begun and ended at the required depth by the dispatch of messenger weights down the suspending wire from above. The copepodCalanus finmarchicus(Gunn.) was used, but a few experiments were also made with another copepod,Euchaeta norvegicaBoeck.The apparatus is described in detail; it takes two forms. No. 1 consists of two vertical parallel glass cylinders AB and αβ closed at the top by a glass plate and at the bottom by a metal one, and having trapdoors at the middle of each which divide them into upper and lower compartments, A and B in one, and α and β in the other. They were filled with sea water and the copepods were introduced injo only one compartment of each cylinder, in standard experiments into A on one side and j3 on the other. The apparatus was now lowered to the required depth and the trapdoors opened so that the copepods were free to move up or down the whole length of the cylinders. At the end of an experiment the trapdoors were closed again so that the percentage proportions that have moved up or down under different conditions could be estimated. In experiments other than standard, one side was left normal as a control and in the other the conditions were altered for the purpose of the experiment, e.g. darkened or the pH of the water increased or decreased. Apparatus No. 2 is a modification, a long tube of seven compartments each separated by a controlled trapdoor.

中文翻译：

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浮游动物垂直迁徙实验

实验是用主要由玻璃制成的设备进行的，专门设计用于研究浮游动物在尽可能自然条件下在海洋不同深度的垂直运动。动物在黑暗中被引入装置中，该装置用黑色布覆盖，直到它降低到水面以下，以便从它们被捕获到不透明的拖网桶中，直到它们被放回大海设备，他们从未受到过表面照明。实验开始和结束时，通过从上方沿着悬索向下发送信使重物，在所需的深度。桡足类凤仙花（Gunn.）被使用，但也用另一种桡足类动物进行了一些实验，Euchaeta norvegicaBoeck. 详细描述了该装置；它有两种形式。1 号由两个垂直平行的玻璃圆柱 AB 和 αβ 组成，顶部用玻璃板封闭，底部用金属封闭，每个中间有活板门，将它们分成上下隔间，A 和 B一个，另一个是 α 和 β。它们充满海水，并且在标准实验中，桡足类仅被引入每个圆柱体的一个隔间中，一侧是 A，另一侧是 j3。仪器现在被降低到所需的深度，活板门打开，这样桡足类就可以自由地在圆柱体的整个长度上上下移动。在实验结束时，活板门再次关闭，以便可以估计在不同条件下向上或向下移动的百分比。在标准以外的实验中，一侧保持正常作为对照，而在另一侧为实验目的改变条件，例如变暗或水的pH值升高或降低。2 号设备是一种改进型，由七个隔间组成的长管，每个隔间由一个受控的活板门隔开。