Nov., 1912.] The Reduction Division in Fuchsia. 15 



EXPLANATION OF PLATES I AND II. 



The plates are reduced f in reproduction. All the figures 

 were drawn with a conpensating ociilar 18, and an oil immersion 

 1/12, which makes a magnification of about 2500. 



PLATE I. 

 Fig. 1. Microsporocyte showing the resting chromatin network. 

 Fig. 2. Microsporocyte showing the chromatin material beginning to 



collect in little lumps. 

 Fig. 3. Later stage showing the further development of the chromatin 



masses. 

 Fig. 4. Microsporocyte showing well formed masses with more prominent 



connections. 

 Figs. 5, 6. Microsporocytes still showing the larger chromatin masses but 



having well formed linin threads on which are seen chromatin 



granules. 

 Figs. 7, 8. Microsporocytes showing the spirem with granules on it and 



still showing some larger masses of chromatin material. 

 Figs. 9, 10, U. Microsporocytes showing the chromatin material in various 



stages of synizesis. 

 Fig. 9. The microsporocyte in contraction showing a few strands on which 



granules may be distinctly seen. 

 Fig. 12. Sporocyte with the spirem well formed, showing a slight disposi- 

 tion to loop. 

 Fig. 13. Sporocyte showing well formed loops. 

 Fig. 14. Sporocyte showing the loops well formed. 

 Fig. 14a. Part of the looped spirem from Fig. 14, showing the small granules 



on the spirem and in one case there are two loops fastened 



together. 

 Fig. 15. Sporocyte showing that the loops have become tightened. 

 Fig. 16. Sporocyte showing loose and tight loops. 

 Fig. 17. Sporocyte in which the loops have separated from each other and 



show characteristic sizes and shapes. 



PLATE IL 



Fig. 18. Later stage of Fig. 17 in which some of the loops have become 



tighter. 

 Fig. 18a. A loop from the top of the nucleus shown in Fig. 18. 

 Fig. 18b. A loop from the bottom of the nucleus in Fig. 18. 

 Fig. 19. Chromosome loops of various characteristic sizes and shapes. 



The nucleolus has disappeared. 

 Fig. 20. Later stage in the formation of the chromosomes. The loops are 



tightening. 

 Fig. 21, The loops have become tighter and have come to lie closer 



together. 



