PLATE XI. 



Fig. 1. 



Fig. 2. 



Fig. 3, 



ttrr 



Fig. 7. 



, 



Fig. 5. 



Fig. 8. 



Fig. 6. 



Fig. 9. 



Dr. H. Van Heurck, phM. Collotype Ptg. Co., zSa High Holborn, W.C. 



TEST OBJECTS FOR THE MICROSCOPE. 



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



