464 C. C. MACKLIN. 



PLATE II. 



FIGS. 13 TO 23. Graphic record of the process of mitosis in a living binucleate 

 cell, from a ig-hour culture of 7-day chick heart, growing in Locke solution (i per 

 cent, dextrose with extract of chick embryo), c, Fig. 13, points to the centrosphere. 

 Camera lucida drawings. X 1,333- (Description in text.) 



