1895.] MICROSCOPICAL JOURNAL. 241 



and diameters measured by the projection of a stage 

 micrometer upon the screen ; the lantern multiplies these 

 diameters by forty, giving on the screen 40,000 and 80,- 

 000 diameters. The time of exposure was instantaneous, 

 at least relatively with regard to the motion of the bodies, 

 varying in different pictures from two, to one-fourth of 

 a second. 



The results obtained as regards the photomicrography 

 of unstained specimens is illustrated by six photomicro- 

 graphs of human blood in the different forms which it 

 assumes upon the warm stages. 



The method of study is illustrated by the following 

 series : — 



Series A. — The amoeboid motion of the white blood cor- 

 puscle. The change of shape and motion with relation 

 to the surrounding stationary and identical fields is well 

 marked. 



Series B. — This series shows the power of the white 

 blood corpuscle in forcing its way through a mass of red 

 crenated and adherent blood corpuscles. 



Series C. — Is of marked interest ; a white corpuscle has 

 seized upon a red corpuscle and a series of photomicro- 

 graphs shows that it has dragged it through a consid- 

 erable distance in a field which is proved to be station- 

 ary and identical in all the photomicrographs. 



Series D. — This series shows motion in a red blood cor- 

 puscle, situated in a field in which the series proves no 

 other motion took place during one-half hour. This 

 motion must, therefore, have been produced by some in- 

 herent power in the red blood corpuscle, and as the pho- 

 tomicrographs show that no twist has occurred, the 

 motion cannot be due to a previous torsion, and may 

 therefore be considered a truly amoeboid motion of the 

 red blood corpuscle. 



Series ERndF. — Show the diapedesis of the red blood 



