Warner: observations on endocladia muricata. 301 



Sexual reproduction. — The cystocarps are found on the 

 branches, sometimes singly, often two on one branch, in which 

 respect this species differs, as has been stated, from E. hamulosa. 

 Beyond the cystocarps, sterile tissue extends in the form of a 

 projection or spine. In a cross section of the cystocarp [Plate 

 XL VI. , Jig. j) slender branching filaments pass in and out 

 among the carpospores. The gelatinous sheath of these filaments 

 is not plainly seen here, the protoplasmic contents alone being 

 visible, and the cells of the filament have become very much 

 distorted. The carpospores are uninucleate and vary in shape, 

 some being spherical, some oblong and others oval. The 

 wall of the cystocarp has the characteristic structure of 

 the wall of the frond. Distorted branches connected at 

 times with the cortical cells are found ramifying through 

 the structure. The development of the cystocarp has been 

 given previously in the paper as described by Schmitz and 

 Hauptfleisch. 



The author desires to thank Professor Conway MacMillan 

 for suggesting the subject for study, Miss Josephine E. Tilden 

 for a detailed outline of the work, and Professor R. A. Harper 

 for encouragement and helpful suggestions during the progress 

 of the work. 



Bibliography. 

 Postels and Ruprecht. Illustrationes Algarum, 16. iS-|o. 

 Harvey, W. H. Nereis Borealis Americana. Part 2. 182. 1S52. 

 Saunders, De A. The Algas. Papers from the Harriman Alaska 



Expedition. Proc. Wash. Acad. 3: Part 1. 1901. 

 Agardh, J. G. Species, Genera et Ordines Algarum, 3 : 55S. 1876. 

 Setchell and Gardner. Algae of Northwestern America. Univ. of 



Calif. Pub. Botany, 296. 1903. 

 DeToni, J. B. Sylloge Algarum, 4: 175. 1S97. 

 Englerand Prantl. Die Natiirlichen Pflanzenfamilien. 353. 1S97. 



Explanation of Plate XLVI. 



All drawings were made by the aid of a camera lucida. 



1. Cross section of the frond. Central axis; small cells surround- 

 ing central axis ; periphery. 



2. Branching of one of the filaments taken about three cells from 

 the central cylinder. Shows somewhat regular branching, similar to 

 the branching of the main axis. At the periphery dichotomous branch- 

 ing is illustrated. 



