ZOOLOGY AND BOTANY, MICROSCOPY, ETC, 
857 
Fig. 91. 
It is made in three forms: — Fig. 89, Sliding coarse-adjustment ; 
fig. 90, rack-and-pinion coarse-adjustment ; fig. 91, with swinging and 
focusing substage carrying Abbe condenser and iris diaphragm. 
1892. 3 M 
