330 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1937 



protoplasm, there can be distinguished fibers that run perpendicularly 

 to the plane of segmentation; these are the connecting filaments of the 

 spindle (fig. 6 at 8:51). 



While the nuclei of the two daughter cells are being constructed, the 

 characteristic checkerboard arrangement taken by the chromatic 

 network may be observed, and there is also noticeable a progressive 

 darkening appearance of the cytoplasm caused by the hemoglobin 

 (fig. 7 at 9 o'clock). 



The daughter cells directly after cell division takes place present a 

 very striking lobular appearance which progressively changes until 

 they return to their definite forms (fig. 8 at 11 o'clock). There 

 can be seen in the upper right of this latest picture a leucocyte trav- 

 ersing the photographic field. 



HAEMOLYSIS OF THE BLOOD 



The photomicrographs of the haemolysis of the blood give a basis 

 for judgment of the hypotheses and theories made regarding the 

 structure of the red blood corpuscles, which have been contradictory 

 up to this time because of the imperfections of the means of ordinary 

 investigations, such as the microscope and the ultramicroscope. 



It should bo remembered that the diameter of the human red blood 

 corpuscle is about 0.0075 millimeter. The red blood corpuscles of 

 several mammals when in contact with hypotonic solution first 

 become spherical, then undergo a slight shock and gradually become 

 pale, showing a contour that is scarcely visible (pi. 8, fig. 1). 



The human red blood corpuscles in an acidulated solution (1/1,000 N 

 hydrochloric acid, for example) swell up, then burst; there may then 

 be observed a white turbidity that starts at one point of the periphery 

 near the exterior, progresses, and soon forms a circular region that 

 results in the flocculence of the proteins expelled from the globule 

 (pi. 8, fig. 3). 



With the action of bile, the nucleated red blood corpuscles of the 

 Triton seem to soften, changing into a cyUndrical or shuttlelike form; 

 then their walls disintegrate, commencing at a point on the periphery, 

 and this destruction proceeds very rapidly in all directions. It is a 

 sort of stripping of the blood corpuscle, the contents of which are 

 then dispersed. As to the human red blood corpuscles, the modifica- 

 tion of the membrane and the dispersal of the globular contents, in 

 the presence of the bile, take place so rapidly that there seems to be a 

 veritable explosion (pi. 9). In the red blood corpuscles of the 

 batrachians there may often be observed animated particles with 

 Brownian movement that are freely displaced. 



The contents of the red blood corpuscle then seem to be liquid. 

 If there is a stroma in the interior, it must be composed of a few and 

 very fine filaments which are invisible even in the ultramicroscope. 



