PLATE I 



EXAMPLES OF LOW-POWER PHOTO-MICROGRAPHY 



(The negatives and reproductions a7e untouched) 



Fig. I. Spinal Cord (Cat) Cervico-MeduUary Region. Photographed with 

 DaUmeyer photo-micrographic rectilinear i'75 inch focus at f/i6 x 6 



Fig. 2. Medulla Oblongata (Cat). Photographed with DaUmeyer photo-micro- 

 graphic rectilinear 175 inch focus at f/i6 x 7 



Fig. 3. Male Spider (Garden). Photographed with Zeiss 50mm. "Planar" at f/£6 



X 2 



Fig. 4. Male Spider (Garden). Photographed with Zeiss 50 mm. " Planar" at f/i6 



X 9 



Fig. 5. Tortoise-shell Butterfly. Photographed with a Petzval portrait lens, 3 inch 

 focus at f/i6 X \\ . 



Fig. 6. Ureter, Section of. Photographed with an ordinary photo-micro-objective 

 used on the camera. It shows purposely the unequal illumination produced 

 by not properly centering the condenser before taking the photograph, 

 and that the lens made for the small field of the microscope has not 

 sufficient covering power and so is not suitable for camera use, as evidenced 

 by the falling off of definition towards the periphery of the specimen, x 10 



Fig. 7. CEsophagus, injected. Photographed with DaUmeyer photo-micrographic 

 rectilinear 175 inch focus at f/i6 x 6 



