326 T. H. BAST 



really undergo cytoplasmic division cannot be stated with cer- 

 tainty, but pictures like figures 10 and 12 afford strong evidence 

 that they do. That the cells in figure 10 are the product of a 

 trinuclear cell can hardly be questioned. The cells in figure 12 

 may have resulted from two mother cells, but it is highly proba- 

 ble that they are the product of a tetranucleated mother cell. 



The centrosomes in these multinucleated cells always lie in 

 the center of the ring of nuclei. In such cells a variable number 

 of centrioles are present. The number of these usually corre- 

 sponds to the number of nuclei, but sometimes the number is 

 considerably larger. This structure seems to correspond to the 

 pluricorpuscular centrosomes which Jordan observed in poly- 

 keryocytes. 



It is a striking fact that in polynuclear cells the cytoplasm is 

 very abundant (figs. 9 and 11). It may be that this large amount 

 of cytoplasm is a factor which determines the number of daughter 

 nuclei into which a given nucleus shall divide. 



Aiiother structure which is common is the non-nucleated mass 

 of protoplasm almost completely separated from the cell. Two 

 such masses are shown in figure 2 and smaller masses in figures 

 7, 8, and 9. In rare cases small bits of nucleoplasm are included 

 therein, as was indicated in my previous paper. Such structures 

 are indicative of cytoplasmic separation without nuclear involve- 

 ment. 



SIGNIFICANCE OF AJMITOSIS 



The place of amitosis in the vital mechanism is a question 

 w^hich has been under critical discussion since Strasburger ('82) 

 and Waldeyer ('88) advanced the view that amitosis in verte- 

 brates was a survival of a primitive process. Since then many 

 theories have been presented, some of which consider amitosis 

 as a degenerative process or the end-stage in the series of cell 

 divisions. Within recent years considerable evidence has been 

 presented which indicates that it may be a normal generative 

 process. 



The following tabulation of the literature indicates the adher- 

 ents to the various theories advanced. 



