Journal of Applied Microscopy. 



559 



One dozen of these were made by special order for use in the botanical 

 laboratory of this institution, and are, as far as I know, the only instruments of 

 the kind in existence. They have been in use two years, along with equally 

 good instruments of the low form. Students are allowed to choose which they 

 will use, and the tall form instruments are always chosen first by the average 

 student, only the student of very low stature thinking the low form will serve 

 him better. 



The lenses were screwed in only sufficiently to hold them firmly, but the 

 students soon found out they were removable, so it was found more satisfactory 

 to screw the lenses into the arm so they could not be removed with the hands. 



E. E. BoGUE. 

 Oklahoma Agricultural and Mechanical College, Stillwater, Oklahoma. 



A Design for a Convenient Staining Dish. 



Since microscopic technique is usually rather tedious, it is desirable to have all 

 apparatus so constructed that it will give the least trouble and care to the inves- 

 tigator. The following design, shown in the figures, is presented as a model for 

 a convenient staining dish. It combines the advantages of the Stender dish and 

 the staining dish, usually made by placing a number of crystallizing dishes 

 inside of each other. 



^i The dish should be made of clear white glass two millimeters thick, with 

 straight, vertical walls and with the top surface accurately ground into a groove in 

 the cover. The cover should be six millimeters thick around the edge. The 





dimensions are as follows : The inside height is eighty millimeters ; height of 

 central part, sixty millimeters ; internal diameter, eighty millimeters ; diameter of 

 central column, sixty -eight millimeters. 



One of the most important points about a staining dish is that it is not easily 

 upset ; another, that only a small amount of the reagent is necessary. The dish 

 described above meets these requirements and is large enough to hold from 

 eight to ten slides at a time. The slides can be transferred with great ease, the 

 only precaution necessary is to place them so that the sections are turned 

 outward. John H. Schaffner. 



Botanical Dept., Ohio State University. 



