486 BOTANICAL GAZETTE ♦ [December 



Since Falkenberg (12) first suggested that Cutler ia and 

 Aglaozonia may represent the two phases of the life cycle of a 

 single species {Cutleria), many workers have tried to secure Agla- 

 ozonia plants from the cultures of fertilized gametes of Cutleria. 

 Falkenberg and Reinke were the only two who succeeded in 

 producing the form Falkenbergiana, an Aglaozonia form. The 

 rest of the investigators succeeded in producing either the form 

 Falkenbergiana or the form Churchiana from unfertilized gametes. 

 Among later workers, Sauvageau, by carrying on his cultures for 

 years, succeeded in getting Aglaozonia or Cutleria from unferti- 

 lized gametes of Cutleria adspersa. The conclusion drawn from 

 this result naturally was that the alternation of generations is not 

 necessary, but rather, as it might be called, facultative. Oltmanns 

 and Strasburger have agreed with this view of Sauvageau. 

 The so-called polymorphic character of Cutleria, however, needs 

 analytical consideration. The results of the author's investigation 

 are as follows: 



The investigation of Cutleria plants bearing gametangia showed 

 that the nucleus has 24 chromosomes in both the vegetative and 

 germ cells. The number is doubled at fertilization by the union 

 of the sexual nuclei. The Cutleria plant is therefore a gametophyte 



chromosome r 

 ! or ege with 



fertilized 



2X- 



gamete 



of the 2#-generation. The studies of the germination of the 

 fertilized gamete have shown that the ix condition continues in 

 further development. The sporeling developed into a structure 



form 



column 



tionally large basal disk expansion which became later the dominat- 

 ing region of the further development. Later this expansion 

 develops the zonal structure of Aglaozonia as found in nature, and 



nuclear conditions, 



mo 



Agla 



nature both having 48 chromosomes. Aglaozonia in nature pro- 

 duces zoospores, during whose formation 48 chromosomes are 

 reduced to 24, and the zoospores contain 24 chromosomes. The 



