$6 EXPLANATION OF FIGURES IN PLATES. 



PLATE III. PHYLLACTINIA CORYLEA. 



FIG. 31. Young ascus with two nuclei; central bodies facing each other. 



FIG. 32. Slightly older ascus ; chromatin strands more conspicuous. 



FIG. 33. Just before nuclear fusion in ascus. Lower nucleus lies above and 

 partially overlapping the 4 other. 



FIG. 34. iSection of ascus with slice of one nucleus showing three chromatin 

 strands and sections of others. 



FIG. 35. Early stage in fusion of nuclei; central body of upper nucleus has 

 pushed ahead on the membrane of the lower nucleus, its chromatin system drawn 

 out in long cone. 



FIG. 36. Stage of fusion. Central bodies and chromatin of two nuclei side by 

 side, but independent; nucleoli already combined in one. 



FIG. 37. Chromatin systems overlapping, but distinct. Nucleoli in contact. 



FIG. 38. (Stage just before the central bodies combine; nucleoli in this case 

 still separate. 



FIG. 39. The central bodies are joined side by side. Chromatin systems com- 

 bining. 



FIG. 40. Central bodies and chromatin systems completely combined. Nucleoli 

 still separate. 



FIG. 41. Shows entire ascus ; stage about the same as in fig. 40. 



FIG. 42.-^Fusion of nuclei complete. 



