8 



PHARMACEUTICAL BOTANY 



But when flowers or other plant parts are to be dissected, it is 

 necessary to have both hands free. To meet this need various 

 forms of stands have been devised which have been combined with 

 an arm and lens to constitute what are known as "Dissecting 

 Microscopes." One of the simpler forms of these is shown in Figs. 

 i and 2. It consists of a low wooden stand with inclined sides that 

 furnish convenient hand rests for the operator. In the center of 



PlG. I. Front view of a dissecting microscope. Description in text. 



FIG. 2. Rear view of same. 



the upper surface of the stand is a glass plate on which the object 

 to be^dissected is placed. Beneath this a mirror is set which reflects 

 light to the object. On either side of the mirror is a hollow cut out 

 which permits light to strike the mirror from various angles. A 

 lens arm fits in an aperture just behind the center of the glass place. 

 The carrier on the end of the horizontal portion of this accomo- 

 dates the magnifier. The arm can be moved up and down or from 

 side to side in securing a focus. The rear of the block is hollowed 

 out, providing a convenient receptacle for dissecting tools. 



