PLATE lY 



EXAMPLES OF HIGH-POWER PHOTO-MICROGRAPHY 



(The negatives and reproductions a7-e untouched) 



Fig. I. Bacillus Tuberculosis in Sputum. The bacillus of consumption as seen in 

 the expectoration. Powell & Lealand ^ apo. N. A. 1-43, with same firm's 

 apo. dry N. A. i-o condenser, projection ocular 6. The bacillus is stained 

 red and background blue. Green screen to increase contrast. x 1000 

 A large solid cone. 



Fig. 2. Bacillus Coli Communis. Photographed under same conditions as Fig. i. 



Bacillus stained violet. x 1000 



Fig. 3. Streptococcus Pyogenes. Photographed under same conditions as Fig. i. 



Bacillus stained violet. x 1000 



Fig. 4. Amphipleura Pellucida. Diatom having lines about 100,000 to inch, Zeiss 

 apo. ^ N. A. 1-40, compens. ocular 18. Conrady 1-35 immersion condenser, 

 " F " line screen, oblique light. Taken direct. x 2500 



Small crescent-shaped diaphragm.-''- 



Fig. 5. Pleurosigma Angulatum. This diatom has three appearances. The 

 " Pearl dot " is here shown above, the " Black dot " beneath : the " White 

 dot " given in Fig. 10. Zeiss | apo. N. A. 1-40. Powell & Lealand dry apo. 

 condenser N. A. I'o. Projection ocular 6. x 1000 



Medium cone. 



Fig. 6. Coscinodiseus Asteromphalus. Secondary markings. Zqiss apo. | N. A. 1-40. 



Powell & Lealand dry apo. N. A. i-o condenser, slight obUquity. Proj. oc. 6. 

 Medium cone. x 1000 



Fig. 7. Eosinophyll Cell. Frog's blood. Photo-micrography applied to physiological 

 specimens. Powell & Lealand apo. N. A. i'43. Projection eye-piece 6. 

 N. A. I'o, dry apo. condenser by same firm. x 850 



Solid cone not quite full size. 



Fig. 8. Navicula Rhomboides. Diatom, secondary markings. Zeiss apo. ^ N. A. 



1-40. Powell & Lealand dry apo. N. A. I'o condenser, "F" line screen, 

 projection eye-piece 6. Photographed at 1000 diameters and enlarged to 

 Nearly full cone. x 1200 



Fig. 9. Surirella Gemma. Diatom, secondary markings, Zeiss apo. | N. A. 1-40. 



Compens. ocular 27. Conrady 1*30 achromatic immersion condenser, con- 

 siderable obliquity, Edwards " Snap-shot " plate. x 3000 



Large crescent-shaped diaphragm.''' 



Fig. 10. Pleurosigma Angulatum. The " White dot " appearance. Photographed 

 at 1200 diameters with same optical arrangement as Fig. 5, and enlarged to 

 Medium cone. x 2000 



Fig. II. Podura Scale. Test object, a scale of Lepidocyrtis curvicoUis. The " black 

 markings " or " notes of exclamation " are well shown. In each is seen a 

 white interior with a constriction at its neck, and having its apex well drawn 

 out. Same optical arrangement as given Fig. 5. x 1000 



Small solid cone. 



Fig. 12. Podura Scale. Enlarged from Fig. 11 to show details of the "note." 



X 2500 



* The crescent-shaped diaphragms mentioned in Figs. 4 and 9 can easily be produced by the iris diaphragm 

 being shifted on one side, in the Zeiss form of oblique-Hght-producer. This is a great convenience, and saves 

 the necessity of preparing different-sized " crescents " to suit different specimens. 



