194 The Ohio Naturalist. [Vol. XIV, No. 1, 



DESCRIPTION OF PLATES IX, X, XI. 



Fig. 1. Microsporocyte in early stage showing the chromatin material. 

 Figs. 2, 3. Microsporoc^^tes showing 7 protochromosomes. 

 Fig. 4. Microsporocyte showing 6 protochromosomes and some reticulum. 

 Figs. 5, 6. Microsporocytes in which some of the protochromosomes have 



been used up in the formation of the spirem. 

 Fig. 7. Fully formed spirem before synizesis. 

 Figs. 8, 9, 10. Different stages of synizesis. 

 Fig. 11. Spirem beginning to show a disposition to loop. 

 Fig. 12. Microsporocyte which shows a continuous spirem that is thrown 



into loops, three of which are plainly visible. 

 Fig. 13. Spirem showing loops. 

 Figs. 14, 15, 16, 17, IS. Microsporocytes showing the spirem thrown into 



loops. 

 Fig. 16. Spirem thrown into seven loops, two of which are double. 

 Fig. 19. Microsporocyte showing the contracted loops which are forming 



the bivalent chromosomes. 

 Fig. 20. Bivalent chromosomes still fastened together. 

 Figs. 21, 22. Microsporocytes showing the seven bivalent chromosomes 



completely formed. 

 Fig. 23. Chromosomes being drawn into the equitorial plane. 

 Fig. 24. Mother star stage. 



Figs. 2.5, 26. Microsporocytes in which the chromosomes are separating. 

 Figs. 27, 28. Metakinesis stages. 

 Fig. 29. Daughter star stages. 

 ~ Beginning of the formation of the nuclear membrane around the 



lower daughter nucleus. 

 Daughter skein stage in which the spindle has not disappeared, 



showing the seven daughter chromosomes in each nucleus. 

 Daughter nuclei before the second division showing the chromo- 

 somes as seven distinct bodies. 

 Mother star of the second division. 

 Microspore tetrad. 



