PLATE XI, 



Fig. 1. 



Fig. 3. 



Dr. H. Van 



Collotype Ptg, Co., 282 High Holborn, VV.C, 



TEST OBJECTS FOR THE MICROSCOPE. 



Objective by C. Zeiss, N.A. roo; Eyepiscs 12. Monochromatic: illumination by sunlight. 



