PLATE LXVII. 



Fig. 1. — Nucleus in the process of synizesis. (x) Accessory chromo- 

 some, la. — Drawings of accessory chromosomes from nuclei similar to 

 fig 1. A, B, C and D indicate the four individuals from which these 

 comparative drawings were made. 



FiG; 2. — Spermatocyte nucleus, immediately after synizesis, showing 

 both accessory chromosomes and the plasmasome. 2a. — Accessory chro- 

 mosomes from the same stage as is shown in fig. 2. 26. — Plasmasomes 

 from the same nuclei as the accessory chromosomes in 2a. The opposite 

 elements in columns 2a and 26 are from the same nucleus. The same 

 holds true for columns 3a and 36, 4a and 46, 5a and 56. 



Fig. 3.— Spermatocyte nucleus, showing a later stage than fig. 2. 

 3a. — Accessory chromosomes from the same stage as fig. 3. 36. — Plas- 

 masomes from the same stage as fig. 3. See explanation of fig. 2, same 

 plate. 



Fig. 4. — Spermatocyte nucleus at the period of maximum diff'usion 

 and largest plasmasome growth, deeply stained. 4o. — Accessory chro- 

 mosomes from same state as fig. 4. 46. — Plasmasomes from same stage 

 as fig. 4. See explanation of fig. 2, same plate. 



Fig. 5. — Spermatocyte nucleus, showing the beginning of chromosome 

 reorganization. 5a. — Accessory chromosomes from the same stage as 

 fig. 5. 56. — Plasmasomes from the same stage as fig. 5. See explana- 

 tion of fig. 2, same plate. 



