977 



pvknotic nuclei are occasionally noled in the linnen entirely def)rived 

 of cyto})lasm. I take it, therefore, that here we have to do with an 

 unmistakable degeneration. 



Further research revealed similar degenerations already in the 

 first week. Also in the spleen-pulpa groups are found here and 

 there presenting an appearance exactly like those afforded by the 

 degenerating giant-cells in the lumen or in the wall of the vessel. 

 The process, then, does not depend entirely on the protrusion into 

 the vessels, which lends additional support to the conception that 

 this protrusion is of a passive, not of an active nature. 



n 



d 



^ 



Fig. 4. Like fig. 3. 570 X natural size, 

 a. megakaryocyte with pyknotic nucleus, reaching only with a narrow point the 

 vessel- wall, h and c degenerating megakaryocytes, especially c is poorly stained. 

 d. degenerating megakaryocyte, e. vessel-wall. 



Not in one instance did 1 see in the lumen of the vessel a normal 

 giant-cell with a beautifully horseshoe-shaped nucleus, which con- 

 firms our conception of the whole process. Now if we observe the 

 preparations from a kitten of three weeks, we note a considerable 

 decrease in the number of giant-cells. This does not surprise ns in 

 the least, considering the extensive dissolution. In the fourth week only 



