o. HEILBOBN, CYTOLOGICAL STUDIES ON CARICA. 11 



OSENBERG (1907) in Hieracium, subgenus P«7o5eZ^a, and thus 

 > regard the above-mentioned supernumerary mother-cells 

 i aposporical. There is, however, a difference to be noted: 

 Carica the failure in chromosome conjugation is not com- 

 ete, which it is in Hieracium. Besides, I do not know, 

 hether the presumptively aposporical mother-cells in Carica 

 ally are capable of development, though this seems by no 

 cans inconceivable. — As mentioned above, I found an 



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g. 11. Somatic rnetaphase of C. pentagona. 12. Heterotypic motaphase 

 embryo-sac mother-ceil of C. pentagona (from Banos). 13. Tlie same 

 motypic metaphase as in Fig. 10. 14. The .same 15-chromosonie ineta- 

 lase as in Fig;. 10. 1.5. Heterotypic metaphase in embryo-sac mother-cell 

 C. pentagona ("from Quito). 10. Heterotypic metaphase in pollen mother- 

 cell of C. candamarcensis- 17. Diakinesis in embryo-sac mother-cell of 

 C. Papaya. — Reich, horn. imm. '/i--, Leitz peripl.-oc. 20 X. 



rule with two mother-cells in C. chrysopetala as well, so 

 lat apospory may perhaps occur in that species too. 



Also in an individual from Quito of C. pentagona I hap- 

 jned to find the heterotypic metaphase in an embryo-sac 

 other-cell (Fig. 15). In that spindle 1 bivalent and 16 

 livalent chromosomes can be easily counted. The arrange- 

 ent of the chromosomes is somewhat irregular and I do not 

 now how they would have behaved during the anaphase, 

 resumably the univalents would have divided, thus giving 



