446 BOTANICAL GAZETTE [December 



Chicago. To Professor John M. Coulter and Professor Charles 

 J. Chamberlain I wish to express my thanks for their suggestions 

 and criticisms throughout the investigation. 



The paper presents the results of my studies on Cutleria and 

 Aglaozonia. For Cutleria there is described the mitosis in the 

 vegetative cells of the male and female plants, the formation of the 

 male and female gametes, the fertilization and the germination of 

 the fertilized female gametes, and the germination of the unfertilized 

 female gametes; for Aglaozonia the mitosis in the vegetative cells, 



■ 



and the formation and germination of the zoospores. Finally, there 

 is a brief discussion of the cytological phenomena and the alter- 

 nation of generations. 



Cutleria multifida 



Cutleria multifida J. Ag. is generally dioecious, and the forms of 

 the male and female plants vary with the localities in which they 

 grow. At one place, the male plants are more broadly multifid and 

 shorter than the female, which are very narrowly multifid and often 

 reach a length of 25 cm. or more; in other localities the reverse is 

 true, that is, the male plants are narrowly divided and larger than 

 the female plants. An extensive comparative study of the forms 

 shows that there is great variability in habit, so that it seems 

 impossible to distinguish the two mature sexual individuals by any 

 gross morphological aspects, except that they bear, as a rule, 

 exclusively either male or female reproductive organs. Cutleria 

 grows in the Bay of Naples upon rocks or mollusk shells, at a 

 depth of 1-5 meters. The Cutleria material was collected with the 

 rocks or shells upon which it was growing, and there was always an 

 abundant display of the successive stages in the development of the 

 plants, from the very young thallus to large adult forms. The 

 young thallus is 1-3 mm. in length, narrowly funnel-shaped, and 

 presents no feature to distinguish the male plants from the female. 



MITOSIS IN THE VEGETATIVE CELLS OF THE MALE AND 



FEMALE PLANTS 



Both male and female plants, when fresh, always bear a beauti- 

 ful fascicle of hairs at the tips of the multifid filaments of the thallus, 

 and scattered here and there upon the whole surface of the thallus 



