PLATE 16 
Fig. 6. Front view (side away from the operator) of constant-tem- 
perature box for microscope. The glass front, which is invisible in the 
photograph, is in place and the apparatus inside is seen through the glass. 
A large 50-degree thermometer (white) is suspended from the glycerine- 
filled tube of the regulator. The bulb of another rests on the stage of 
the compound microscope in contact with the circulation slide. 
Fig. 7. Rear view of the constant-temperature box. Between the 
microscopes lies the small (white) rubber tube through which the air of 
the waste bottle is exhausted and the current started in the slide. The 
drawing shelf and camera mirror are at the right. 
[134] 
