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THE AMERICAN NATURALIST [Vol. XLVII 



that pollen is not essential for the perfecting of Euphor- 

 biaceae seed. In 1857 A. Brann described Chara crinita 

 Wallr. as a true case of parthenogenesis. In 1877, Stras- 

 burger with the aid of modern technique found that the 

 embryos in Ccelebogyne ilicifolia were formed without 

 fertilization, but that parthenogenesis was absent, as the 

 embryos came not from unfertilized eggs, but from ad- 

 ventitious growths (Sprossungen) of the nucellus tissue. 

 In 1900, Juel definitely proved its existence in Anten- 

 naria, thus establishing its presence in the higher plants. 



As botanical investigators do not always agree in the 

 use of the terms parthenogenesis and apogamy, Winkler 

 divides all reproductive phenomena into three divisions, 

 namely: Amphimixis, Pseudomixis, and Apomixis. 



1. Amphimixis, which designates the normal sexual 

 process. 



2. Pseudomixis, which means the replacement of true 

 sex-cell fusions by a false sexual process. Pseudomixis 

 thus differs from amphimixis, essentially, only in the cir- 

 cumstance that the fusing cells are not differentiated as 

 gametes. As an example of the pseudomictic (pseudo- 

 miktische) method of reproduction is cited Lastrea pseu- 

 domas var. polydactyla Wills, in which the sporophyte 

 arises from a prothallium cell, its primordial nucleus 

 fusing with a nucleus from a neighboring cell. Farmer 

 and Digby (1907, p. 191) name this procedure "pseudo- 

 apogamy." All non-sexual nuclear or cell fusions must 

 not be considered as pseudosexual, however, for there is 

 an asexual cell fusion in addition to the sexual and the 

 pseudosexual, as, for example, the nucleus fusion de- 

 scribed by Nemec (1902, 1903) in chloralized roots of 

 Vicia, and also the frequently mentioned nucleus fusion 

 in the young ascus of the Ascomycetes. 



3. Apomixis, which is the replacement of sexual repro- 

 duction by another, an asexual process, which is not 

 bound up with nuclear fusions. For it, there is already 

 another term, namely that of apogamy. This latter term 

 was applied by de Bary (1878, p. 479) for the fact, "dass 



