I j,S H. L. RATCLIFFE. 



EXPLANATION OF PLATES. 



PLATE i. 



All figures drawn with camera lucida. Fig. i drawn at a magnification 

 of 1,100 diameters. All other figures drawn at a magnification of 825 

 diameters. 



FIG. i. Vegetative form of Euglcna spirogyra. Chromatin at this time 

 in the form of paired rows of chromomeres. All other structures to which 

 reference is made are labeled. 



FIG. i, a, b, c. Early prophase stages showing forward movement and 

 division of intranuclear body. 



