208 



PHASE MICROSCOPY IN BIOLOGY AND MEDICINE 



preparations of the cornea of the frog and rat with a 0.2A— 0.25X dif- 

 fraction plate, although the overlying cells somewhat obscure the detail, 

 even in an unstained preparation. Chromosome movements were 

 measured by Hughes and Swann (1948) on biframe motion picture films 

 made with phase microscopy to show the chromosomes and with polarized 

 light to show the spindle. These films appear to support a traction 

 theory of chromosome separation in embryonic cells of the chick. 

 Enhanced contrast is possible from combining phase contrast with that 

 of staining'^ (Fig. IV.4). By combining phase and polarization cine- 

 microscopy Hughes and Fell (1949) were able to see both the chromo- 

 somes and the spindle during mitosis. 



Fig. V.5. Drosophila salivary gland chromosomes, fixed unstained smear mounted 

 in Clarite, 650 X. f-icft, brightfield. Center, bright-contrast phase. Right, dark- 

 contrast phase. 



Mitochondria and tonofibrils were described by Albertini (19466). 

 Jones (1947c; 19486) combined phase with staining methods for the 

 analysis of mitochondrial behavior in embryonic blood cells of the rat. 

 He preferred medium l)right and dark (A — ) contrasts for unstained, 

 fixed cells and the 2.5B— 0.25X for Soudan Black stained preparations. 

 Ludford et al. (1948) recommended phase for observing mitochondria. 

 The mitochondria of flattened tissue culture cells show especially well 

 (Firor and Gey, 1947). 



The Golgi apparatus shows in enlargements of the epithelial tissue 

 figured by Eichards (19446). Brice et al. (1946) discovered this ap- 

 paratus in smears from the seminal vessicle of Lumbricus, and Oettle 

 (1948) saw it in the testicular cells of man. Jones (1947a, 19486) and 

 Corti (1948) reported seeing the Golgi apparatus, but Zollinger (1948c) 

 failed to find it. Baker (1949) preferred dark (A — ) contrast for the 

 examination of this and recommends calling it, instead, the Golgi 



