CLARK: CYTOLOGY OF CARCINOMA. 211 



characteristics was considered a cell change having as its 

 ultimate end either the production of new cells or degeneration. 



Among the resting cells were others which could be easily 

 identified as being in the process of indirect division. Al- 

 though no detail of the chromosomes could be made out, yet the 

 increased amount of chromatin over the resting cell, its affinity 

 for the stain, the irregular outline of the chromosomes, the ab- 

 sence of the nuclear membrane and the shape and position of 

 the chromatin masses identical with those of the prophase, 

 metaphase, anaphase, and telophase leave no doubt as to the 

 identity of such cells. Equally distributed among the resting 

 cells were other cells which were clearly abnormal, owing to 

 their unusual size and their content of two or more nuclei or 

 clefts of greater or less depth which either separated or tended 

 to separate the single nucleus into two or more distinct seg- 

 ments. These separated segments had all the characteristics 

 of the nucleus of the resting cell. I have considered such cells 

 as in the process of direct cell division, although I have been 

 unable to find a single cell showing distinct separation of the 

 cytoplasm. Adami thus describes amitosis : "The nucleus 

 divides without any apparent preliminary rearrangement of 

 its structure. It becomes elongated, then dumb-bell shape (the 

 process can be followed in the amceba), the connecting neci<: 

 becomes broken across and the two daughter nuclei pass apart, 

 their separation being in some cases followed by division of the 

 cell body while in others this further division is wanting and 

 the binucleate cell is produced." Patterson, in "Amitosis in 

 the Pigeon's Egg," says : "In most cases the nucleus elongates 

 in the direction transverse to the plane of the future division, 

 after which a constriction in the nuclear membrane appears 

 about the entire circumference of the nucleus. This con- 

 striction continues to deepen until a complete division is ef- 

 fected. A modified form of this type is found in those cases 

 in which the constriction proceeds from one side." 



Although the process in this material differs somewhat, I 

 think, from that described by Adami and Patterson for other 

 material, the result is the same. Therefore I feel safe in as- 

 suming that cells with the nucleus wholly or in various degrees 

 of separation are in the process of amitosis. Ziegler and 

 Vom Rath consider such cells as already in the process of de- 

 generation. If so, it will not be out of place to consider along 

 with these division figures structures that appear throughout 



