70 F. B. BANG 



of pinocytotic droplets as they are carried to the center of the cells 

 {Geyetal, 1955). 



C. Mitochondria 



The mitochondria have long been recognized as sensitive indicators of cell 

 metabolism, but this phrase has had little specific meaning. The recent 

 knowledge of their detailed structure and of the localization of numerous 

 enzymes in them would in itself raise questions concerning the nonspecific 

 implications of the quotation. Furthermore, it is now clear from several 

 studies that extensive changes may occur in a virus-infected cell without 

 any apparent change in the mitochondria. Thus, the future aim will be to 

 describe specifically what changes, if any, are caused by viral lesions. Bal- 

 looning of mitochondria occurs frequently in degenerating cells. That this 

 osmotic lesion occurring in specific organelles may not be a distinctively de- 

 generative change is indicated by the fact that it may be induced by thyroxine 

 (Schulz et al., 1956), and that mitochondria may be specifically kept from 

 swelling due to thyroxine by the production of anaerobiasis (Lehninger and 

 Ray, 1957). Furthermore, Luft and Hechter (1957) report that the distended 

 vacuolar mitochondria seen in electron micrographs of adrenal glands ob- 

 tained from slaughter houses may be converted to a normal appearance by 

 the perfusion with warm, oxygenated beef blood. Such changes are then 

 significant in relation to the idea that tumors may involve lesions of the 

 mitochondria. Degeneration or disappearance of the mitochondria in dying 

 cells has also been described (Lewis, 1923; Lewis and Lewis, 1924). 



D. Paranuclear Hypertrophy 



Since the discussion concerning the nature of the "Golgi apparatus" 

 continues (Pollister and Pollister, 1957; Baker, 1957), we will limit this 

 review to a discussion of the tissue culture findings concerning the para- 

 nuclear area. It is particularly in the tissue cultures of poliomyelitis infections 

 that lesions have been described. Lewis (1920) described "giant centro- 

 spheres in degenerating mesenchyme cells." The term "centrosphere" was 

 used to designate a peculiarly differentiated region about the centriole. The 

 lesions range from slight vacuolization around the centrosphere to an en- 

 larged centrosphere with sharp borders, medullary and cortical zones, and 

 concentric or radial arrangement of mitochondria about the centrosphere. 

 Lewis emphasized the importance of this degenerative lesion because of an 

 apparently identical phenomenon in certain cancer cells. 



E. Hypertrophied or Giant Cells 



The presence of giant cells in tissue cultures of all kinds is not rare (Lewis 

 and Lewis, 1924). It was early described by Lambert and Hanes (1911) in 



