PLATE 36. 



Living Micro-organisms. 



A Micrococci FOUND IN ROPY BEER x 1000 



B BREWING YEAST, Saccharomyces cerevisice x 700 



C Spirochaeta pallida, PURE CULTURE x 1000 



D BREWING YEAST X 700 



E A "WILD" YEAST, Saccharomyces Sp? x 700 



A tendency to collect together in masses is characteristic of this 

 yeast. 



A B and E 



Objective Zeiss4mm. Apochromat. 



Ocular Zeiss Compens. x 12 Watson's Holos. 10. 



Condenser . ... Watson's Universal Achromat, with iris closed 



so that only about ^ of the aperture of the 

 objective is employed. In A and E the 

 light is a trifle oblique, the condenser just 

 out of centre, giving "solid" appearance. 

 Illuminant ... Liliput 4 amp. arc. 



Aux. Condenser Bull's-eye for parallel light. 



Screen ... ... None. Wratten's B, green. 



Plate ... ... Wratten's Ilford 



Panchromatic. Panchromatic. 



Exposure -i- sec. 1 sec. 



Camera Vertical, the micrococcus was in rapid 



vibratory motion. 



C D 



Dark ground illumination. 



Objective Leitz 2 mm. Baker's T V 



Apochromat. oil immersion. 



Ocular Leitz Compensating, 8. Watson's Holos. 10. 



Condenser ... Leitz dark ground. Nelson's dark ground. 

 Illuminant ... Liliput 4 amp. arc. 



Aux. Condenser Bull's-eye convergent light. 



Screen None. 



Plate Wellington Anti-Screen 



Ortho. 

 Exposure Instantaneous. 5 sec. 



Details of manipulation given on page 243. 



Photos. C by LEITZ ; others, H. L. H. 



To follow page 244. 



