Considerable study of Aceria tulipae has been made since the discovery that this eriophyid mite is a vector of the virus of yellow streak mosaic of wheat. The leaves upon which the mites feed and propagate soon become rolled, making examination for them and their eggs difficult. About 30-power magnification is required to see these mites plainly. The best instrument for their study is the binocular stereoscopic wide field microscope. Lacking this, any microscope may be utilized by using a 40 mm objective or an ordinary low power objective with the outer lens removed. This paper describes various pieces of equipment that have been devised to make the study of mites easier. It is hoped that it may stimulate the development of other helpful devices. Device No. 1 (Fig. 1A and B) was designed to keep the surface of the leaf under study in constant focus and also to aid in straightening a rolled or crinkled leaf. The one used by the author is shown separately in Figure 1A and in place on a microscope stage in Figure 1B. The base is of 1/8 x 3/4 inch brass with a length to suit the microscope stage on which it is being used. The uprights are formed from a piece of sheet copper bent up at both ends and soldered onto the base. The copper tube of 1/4-inch outside diameter is soldered to the holes in the two uprights. A convenient height above the base for the upper surface of the tube is about 7/8 to 1 inch. The device is attached to the stage with a pinch clamp with the tube directly under the objective so its upper surface is in focus. A leaf is grasped at its extremities and slowly pulled lengthwise over the tube.

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