Grinnellia americana, Harv. 25 



of highly refractive, yellow cells at the base of the procarpium. 

 It differs in that the pericarp is only two to three layers of 

 cells in thickness, and that no fusion of cells is observed in the 

 basal cystocarpic region of Grinnellia. As previously stated, 

 this is one of the most salient points developed in the study 

 of Grinnellia. This subject was more interesting, and received 

 more special attention, because fusion of cells in the basal 

 cystocarpic region had been reported for other Florideae, 

 notably the closely related genus Gracilaria. 



16. It is perfectly evident that fusion of cells in the basal 

 region of the developing cystocarp does not occur ; but that 

 the large amount of nourishment supplied to the ooblastema- 

 iilaments by the cells growing directly from the joint-cell at 

 the base of the cystocarp, is received directly through the pits 

 from the group of densely protoplasmic auxiliary cells in the 

 floor of the fruiting body, and indirectly, by transmission from 

 the pericarp through the sterile filaments. 



17. Grinnellia americana conforms in every phase of de- 

 velopment to Schmitz's law of apical growth. This law is 

 exemplified in the germination of the spores, the growth of 

 the fronds, the origin and development of antheridia and 

 cystocarps, and the final separation of antherozoids and 

 carpospores. 



State University of North Dakota, 

 Grand Forks, North Dakota. 



References to Literature. 



Collins, F. S. In Notes on New England Algae, III, Bull. Torr. Bot. Club II : 

 29, 30, Mr. 1884. Records a striking exception to the rule, the presence 

 of characteristic south shore New England Algae north of Cape Cod in 

 Weymouth River and an adjoining cove. 



Farlow, W. G. The Marine Algae of New England. U. S. Fish Com. Report, 

 1879, pp. 161, 162. 



Harvey, W. H. Ner. Am. Bor., Part II. 



Potter, M. C. Jour. Marine Biolog. Ass., pp. 171, 172. 1889. 



