It is clear that much remains to be done in the cytology of 
Erythroxylum. The study of cytogenetics has been essential in 
determining the origin and evolution of numerous cultivated 
plants. Erythroxylum should be no exception. Of initial, pri- 
mary importance is an investigation of karyotypes and chro- 
mosomal behavior in the main cultivated forms of E. coca and 
E. novogranatense, as well as in related wild species. 
LITERATURE CITED 
Darlington, C.D. and E.K. Janaki Ammal. 1945. Chromosome Atlas of 
Cultivated Plants. Allen and Unwin. London. 
Heitz, E. 1929. Heterochromatin, Chromocentren, Chromomeren. Ber. 
Deutsch. Bot. Ges. 47: 274-284. 
Mangenot, S. and G. Mangenot. 1958. Deuxieme liste de nombres chromo- 
somiques nouveaux chez diverses Dicotyledones et Monocotyledones 
d'Afrique occidentale. Bull. Jard. Bot. Bruxelles 28: 315-329. 
Mangenot, S. andG. Mangenot. 1962. Enquete sur les nombres chromosom- 
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25: 411-447. 
Mehra, P.N. and P.K. Khosla. 1969. /n A. Love, IOPB Chromosome Num- 
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Tijo, J.A. and A. Levan. 1950. The use of oxyquinoline in chromosome 
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