242 THE AMERICAN MONTHLY [Aug, 



corpuscle from a capillary in wliicli the blood is in motion 

 and from one in which there is the stasis of the blood. 

 This phenomenon, therefore, occurs under two opposite 

 conditions as regards intra-vascular blood pressure, indi- 

 cating, perhaps, that diapedesis is not a filtration due to 

 pressure, but is due to the amoeboid motion and power of 

 the red blood corpuscle. 



Series G. — This series shows an empty capillary 

 Along the inner surface of its wall maybe seen white 

 corpuscles, in which the series indicates movement. 

 The diapedesis of two red blood corpuscles from this 

 empty capillary tends to strengthen the belief in the 

 amoeboid motion of the red blood corpuscle. 



Further photomicrographs illustrate the position of the 

 corpuscles within the capillaries, and show the presence 

 of nuclei in the red corpuscles of the frog while in the 

 living tissues. DiflFerent forms of the malarial plasmodia, 

 and the application of the method to pathological studies 

 are illustrated by other photomicrographs. 



The pictures are not shown as the perfect result of 

 this method, or as the outcome of research by it. They 

 are simply to illustrate the author's method of studying 

 cell motion. Inferences based on the pictures are 

 foreign to the purpose of the communication, which is 

 intended merely to demonstrate a method of study 

 worthy of scientific consideration. Its usefulness in 

 producing accurate illustrations, both for publication and 

 for lantern slides, cannot be over-estimated, as it sup- 

 plies pictures whose counterpart can be found under 

 the microscope. 



Catalogues of W. & H. Seibert are supplied by Fr. J. Em- 

 merich, Sr., No. 74 Murray St., New York, N. Y. O. E. S. 



