DEPARTMENT OF EMBRYOLOGY. 89 



ments are quite different in character from those of the granules. In 

 the giant-centrosphere type the intervacuolar framework is not appar- 

 ent, but there is a more deeply staining cytoplasm concentrated about 

 the centrosphere, and in it lie the mitochondria in addition to the 

 granules and vacuoles. 



An interesting similarity to certain cytoplasmic inclusions in cancer 

 cells is presented by the enlarged centrospheres in these degenerating 

 cultures. From his observations Dr. Lewis feels justified in regarding 

 them, as also the neutral red granules and vacuoles, as degenerative 

 changes. In normal ceU division there is a similar enlargement of the 

 centrosphere and the etiological factors involved in the two processes 

 are probably identical. In the normal cell, division is completed and 

 the metabolic balance restored, whereas in the abnormal cell something 

 prevents the completion of mitosis and death of the cell follows. Since 

 this enlargement is found both in degenerating mesenchyme cells and 

 in the epithelial cells of cancer, it is quite conceivable that it may not 

 be limited to these two types, but may be found in other pathological 

 conditions of the tissues. The fact that it occurs in the cells of tissue 

 cultures, where we can more or less control the environment, brings 

 w^ithin the realm of experimental solution the factors which cause this 

 condition. 



The important observations of Dr. Lewis on degeneration vacuoles in 

 fibroblasts have been supplemented by Miss R. E. Prigosen in a study 

 of the same phenomenon in blood cells. She has made a preliminary 

 conmiunication reporting the vacuolization of red blood cells in the 

 chick and of leucocytes in human blood. 



In order to test the behavior of cells under different chemical condi- 

 tions. Dr. P. G. Shipley grew tissue from chick embryos in plasma and 

 noted the reaction of the cells to various vital benzedene dyes, to col- 

 loidal silver and manganese, and to particulate foreign materials. 

 Included with his observations is a full discussion of the course of events 

 following vital staining of the cell — how the color enters the cells and 

 in what state it exists in the cytoplasm. He finds that the same factors 

 prevail where the cell stores up colloidal proteins and other finely 

 divided materials useful in the metabolic processes of the body. His 

 observations on neutral red granules and vacuoles are of interest, in 

 that he does not regard them as evidences of degeneration, but rather as 

 segregation granules and vacuoles, diverging in this respect from W. H. 

 and M. R. Lewis, whose observations on these structures, as seen in 

 cultures grown in salt solution, are described in this and previous re- 

 ports. Shipley maintains that all foreign material, especially particu- 

 late matter, which enters the cell finds its way into these vacuoles and 

 becomes an integral part of the contained granule. According to his 

 view, the segregation granule, analogous to the food vacuole of pro- 

 tozoa, consists of the aggregated material which the cell has gathered 



