632 GRIFFJN. 



EXPLANATION OF PLATE XXXIIL 



( Thalassemia melliia.) 



Figs. 34-36. Various stages in copulation of germ-nuclei, showing persistence 

 of centrosomes throughout entire period. 



Fig. 37. Segmentation nucleus ; renewed activity on part of centers. 



Fig. 38. Later stage, chromatin of nucleus in spireme stage. 



Fig. 39. Mitotic figure almost completed ; spireme segmenting into the chro- 

 mosomes ; centrosomes divided. 



Fig. 40. Transverse section across equatorial plate. 



Fig. 41. Beginning of anaphase; centrosomes migrating to periphery of 

 centrosphere. 



Fig. 42. Anaphase ; the centrosomes at the periphery and widely separated. 



Fig. 43. Later anaphase; the new amphiaster on the periphery of the former 

 centrosphere. 



Fig. 44. Telophase; chromosomal vesicles formed and beginning to fuse ; a 

 distinct amphiaster. 



Fig. 45. Later stage ; nucleus reconstituted. 



Fig. 46. Two-cell stage, preparing for the second cleavage ; " cell-plate " and 

 engulfed polar bodies between the blastomeres. 



