Plate III. 



41. Two germ-nuclei immediately prior to their conjugation. The sperm- 

 spindle lies between the nuclei, x 86G. 



42. Two germ-nuclei opposing each other. The sperni-spindle is behind 

 the nucleus. X 8GG. 



43-44. Two sections (not consecutive) of germ-nuclei fused. Two cen- 

 trioles are present. Position of the centrioles in the degenerating asters. 

 Small ray systems have appeared around the centrioles. X 86G. 



45. Two germ-nuclei opposing but not yet fused. A centriole (sketched 

 in from the next section) has already acquired a new ray system. X 86G. 



4G. Segmentation nucleus with the sperm-spindle on one side. X 8GG. 



47. Centrosome containing two centrioles at a pole of the first cleavage 

 figure. X 2000. 



48. Centrioles separated farther from each other with two connecting 

 fibres between them. X '-000. 



49. Centrosome enlarging. X -000. 



50. Centrosome still enlarging, its alveolar nature becoming apparent. 



X 2000. 



51. Centrosome with the centrioles connected with a single fibre. X 2000. 



52. Centi'osome, in which the centrioles have taken their definite posi- 

 tion. X 2000. 



53. Centrosome containing centrioles with new rays. X 2000. 



54. Aster in a blastomere of a parthenogenetic egg of Afiterias, showing 

 the relation between fibrous and non-fibrous rays. X 1566. 



55. Parasitic asters on a ray of the central aster of the first maturation 

 figure. X 866. 



56. Kai\vomere rays in a blastomere of Corcgomis. Diastem along the 

 equatorial plane. X ^-^S. 



57. Aster near the egg-nucleus in a parthenogenetic egg of Asferius. X 156r». 



