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1907] PACE— FERTILIZATION IN CYPRIPEDIUM 



373 



sporo 



Fig. II. Same. 0\aile with mother cell in late prophase or m metaphase; 

 origin of spindle indicated by Imes of cjtoplasm. 

 Fig. 12. Same. Eleven chromosomes. 

 Fig. 13. C. spedabilis. Eleven chromosomes. 



Fig. 14. Same, ^^''aIl cell of o^oile showing twenty -two chromosomes 

 phyte niunber). 



Fig. 15. C. puhescens. Typical spindle of mother cell. 



Fig. 16. C. spectabile. Daughter cells formed by division of mother cell. 



Fig, 17. C. pubescens, DaughterceUs; with chalazal nucleus farther advanced 

 than the micropylar. 



. Fig. 18. C spedabile. Suggestion of bipolar spindle. 

 Fig. 19. Same. Metaphase of second division, longitudinal splitting of 

 chromosomes. 



Fig. 20, Same. Telophase of chalazal daughter cell; no indication of wall. 



Fig. 21. C. parvifloncm. Division of chalazal daughter cell complete; 

 remains of spindle, but no evidence of wall. 



Fig. 22. C spedabile, Micropylar daughter nucleus developing and the 

 chalazal one disintesratins. 



o'^ "■•■■'"& 



Fig. 23. C. parvifloriun. Division shown in fig. 21 completed; the sac 

 slightly enlarged and containing two megaspore nuclei. 



Fig. 24. C spedabile. Early spirem for the division of the megaspore 

 nuclei; micropylar daughter cell still recognizable. 



Fig. 25, Same. Spindles for division of megaspore nuclei; micropylar 



persists 



Same 



PLATE XXV 



Fig. 27. Same. Four -nucleate sac, the nuclei differing in size. 



Fig. 28. Same. Nucleus at antipodal end of sac in late prophase; the other 

 in late telophase. 



Fig. 29. C. parviflorum. Embr>'o sac ready for fertilization, showing egg 

 apparatus and "polar" nucleus (near center). 



Fig. 30. Same. Another view of sac, showing polar nucleus near antipodal 



end. 



Fig. 31. Same. Two mother cells. 



Fig. ^2. C. spedabile. Spindle of mother cell at right angles to its usual 



* . • 



position. 



Ftg. ;i^. Same. Four megaspore nuclei of equal size; no walls at second 

 division. 



Fig. 34. C. parviflorum. Four megaspore nuclei, as shown in fig. 33, but 

 the inner pair the larger. 



Fig. 35. C. spedabile. Four megaspore nuclei; traces of spindle showing, 

 but no trace of wall. 



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