172 METHODS IN PLANT HISTOLOGY 



equipped. In the absence of such equipment very satisfactory work 

 can be done with any ordinary camera, microscope, and suitable light 

 source if the worker will exercise sufficient care in their arrangement 

 and alignment. If the camera has a long bellows draw, it should be 

 possible to make pictures with magnifications as great as 1,000 di- 

 ameters. Without regular photomicrographic equipment it is scarcely 

 worth attempting higher magnifications. 



In arranging the equipment for taking a photomicrograph it is ab- 

 solutely essential that all the equipment be in perfect alignment. This 

 is taken care of in the expensive photomicrographic cameras by pro- 

 viding a heavy metal bed or track to which all of the equipment can be 

 attached and along which the various parts can be shifted as necessary 

 in arriving at the correct optical adjustment. A satisfactory substitute 

 for this rigid optical bed can be constructed from a board of sufficient 

 length to accommodate all of the equipment. A guideway for the 

 camera can be made of wooden strips and screwed to the board. The 

 microscope can be bolted to the board by long bolts with buttei-fly 

 nuts. The microscope is inclined at 90°. The guideway for the camera 

 must be of a sufficient height to raise the camera to a level which will 

 center it with the microscope. If a table can be spared, it might be 

 found to be more convenient to have one table set apart for photomi- 

 crographic work (Fig. 33). A guideway could be fastened to the table, 

 and holes could be bored in the table for bolting down the microscope. 



In the discussion that follows it will be assumed that a photomicro- 

 graph of a part of a vascular bundle is desired and that the photograph 

 is to have a magnification of approximately 400 or 500 diameters. 

 Furthermore, it will l^e assumed that the section has been stained in 

 safranin and anilin blue. 



The apparatus is arranged as follows. The microscope is inclined at 

 the inclination joint. The lens of the camera is removed, and the tube 

 of the microscope is inserted through the hole in the lens board. Some 

 sort of light-tight arrangement must be made where the tube of the 

 microscope enters the camera. A piece of black velvet will serve if 

 carefully wrapped around the tube of the microscope. The microscope 

 is lined up with the camera as accurately as possible and bolted in 

 place. The mirror of the microscope is removed and the light source is 

 placed in line with the camera and the microscope. The light source 

 may be an arc light, a gas lamp with incandescent mantle, a concen- 

 trated filament mazda projection bulb, or a lamp designed especially 



