2^0 Ost en leid. 



species of Taraxacum {T. cotifertnm Dahlst.) must be supposed to be 

 sexual. Taraxacum was hitherto taken to be the only example of a 

 wholly apogamic genus. Further, it applies to Elatostcma, Thalictrum, 

 IMkstroeviia, Alchimilla, Rosa and Balanopliora. We do not know 

 the condition in Thismia, Burmannia, Sciaphila and Meiosis — all 

 saprophytic or parasitic plants — as cytological investigations have 

 not yet embraced other species of the genera named than the apogamic 

 ones here enumerated. Lastly, it has to be added that Hoiittuynia 

 is a monotypic genus. 



Another noteworthy fact with regard to apogamic plants is that 

 comparatively many apogamic plants are pale, chlorophyll- 

 wanting saprophytes or parasites, viz.: Sciaphila, Thismia, Bur- 

 mannia coelestis, Balanophora and Meiosis. Whether this fact may be 

 of some importance or is casual, is difficult to decide at present. 

 A. Ernst and Ed. Schmid are no doubt right in saying in their 

 paper on the normally sexual Rafflesia patma Bl. (1909, p. 184): "so 

 wird man auch bei anderen Parasiten in der Annahme von Be- 

 ziehungen zwischen Reduktion der vegetativen Organe und Anomalien 

 in der Embryosackentwicklung mit oder ohne Apogamie vorsichtig 

 sein müssen." 



The list shows, however, a third fact worthy of interest and which 

 has already called forth many considerations, that is, the evident 

 relation of apogamy to polymorphism. We must here except 

 the pale saprophytes and parasites, and further Mouttuynia, in which 

 we know nothing about polymorphism. But with these exceptions 

 all the hitherto thoroughly examined cases of apogamy (in the dicoty- 

 ledons) fall within polymorphic genera, that is, genera in which at 

 the present time an intense evolution of species is supposed to be 

 taking place. Tiie polymorphism in Alchimilla, Rosa, Taraxacum and 

 Mieracium is well known. In Antcnnaria we find polymorphism in 

 North America (not in Europe), in Thalictrum both in North America 

 and in Northern Europe; Elatostema is a "critical" genus. Finally, 

 H. Winkler (1908, p. 147) and Strasburger (1909, p. 85—87) have 

 shown that Wikstroemia indica is a polymorphic species, of which for 

 the present only the examined "race" from the Buitenzorg Gardens 

 has been proved to be apogamic, while others seem to be normally 

 sexual. Thus it cannot longer be used as an instance of "Apogamie 

 ohne Polymorphismus" (Tischler, 1908, p. 139)1)- 



1) It would also agree very well with the relation of apogamy to polymorphism, 

 if R. R. Gates (1909b) is right in his new supposition, that Oenothera lata, one of 



