CH. X] 



CABINETS AND TRAYS FOR SPECIMENS 



343 



in later trays, but there still remained a defect, for if one wished to 

 pile up five to twenty trays on the table, they would not stay in an 

 even stack. To remedy this defect the long way of the frame was 

 tongued on one side and grooved on the other, as shown in fig. 207. 

 This is a great improvement, as one can make even stacks of 25 or 

 50 trays, and they will stay in position. Furthermore it renders the 

 groups of five trays stored in the locker compartments much easier 



o 



FIG. 206. SIMPLEST FORM OF SLIDE TRAY. 



A Face view of the slide tray. The screw eye at the lower end is convenient 

 for pulling out a single tray. 



B Sectional view of the tray showing the thin board of which it is made and the 

 wooden frame. 



C Sectional view showing how the frame is fastened to the board. 



to manage, as one can remove any of the five trays without getting 

 the others disarranged, as so often occurred with the old form, lacking 

 tongue and groove. 



A defect of the trays for storage is the ease with which the slides 

 get disarranged unless the tray is entirely full. To overcome this 

 defect Mrs. Gage divided one face of the tray into columns (fig. 207) 

 by means of stout cord held in place by using melted paraffin as a 

 cement. Later Dr. Greenman of the Wistar Institute divided one 



