06 



F. B. BANG 



this review we intend merely to describe the changes which have been found 

 there. 



In the accompanying diagrams we have limited the description to a cell 

 in the intermitotic phase of its life. We have excluded any specialized 

 functions. Yet, in the case of the tumor cell, major emphasis has rested with 

 the abnormal behavior of the nucleus during division, and it is primarily on 

 the differentiated or specialized cell that a virus acts in the intact animal. 

 Despite the recent advances, there remains little new in our knowledge of 

 the morphological effects of viruses on specialized cells. 



Fig. 2. Diagram of tissue culture cell showing varieties of cell activity. Process of 

 pincytosis (Pin) indicated as bringing vacuoles into paracentral area of cell where they 

 associate with lipid droplets (LX>) and other inclusive droplets (ID). Continual extrusion 

 of microfibrils from surface of cell, the accumulation of fluid which is milked toward the 

 cell is indicated at left. Rotation of nuclei within cell indicated by arrows. 



Some morphological aspects of cell physiology also need brief review before 

 proceeding. The change in shape which occurs when compact, rounded cells 

 are placed on a new surface, such as glass, has been studied particularly in 

 the blood cells. This change is often accompanied by the loss of granules, the 

 formation of long cellular projections, and, of course, an extreme flattening of 

 the cytoplasm. Cells may, however, be equally extended in the intact 

 animal when covering a surface such as the alveolar cells of the lung (Karrer, 

 1956) or the endothelial cells of blood vessels (Palade, 1956). Thus, tissue 

 culture cells do not necessarily differ from similar cells in shape and relation 

 to other cells. 



