1922] Gardner: The Genus Fncus on the Pacific Coast 17 



The Fucus furcatus of Tilden's American Algae, no. 234, as to the 

 specimen distributed in Professor Setchell's copy, is not typical of this 

 species as found on the California coast. The specimen is only a small 

 portion of a plant. It is mature, considerably worn and battered, and 

 has comparatively few caecostomata. The distribution is probably to 

 be referred to f. typicus, but it is desirable to consult other specimens 

 of the distribution before deciding definitely. 



This form is abundant on the California coast, but less common 

 toward the north, being supplanted by numerous other forms. It 

 reaches its optimum growth in localities where the surf is only moder- 

 ately active. In such situations it attains its greatest height, not 

 infrequently specimens attaining a height of 4.5 dm., but when on 

 boulders exposed to a heavy surf, it remains much shorter, is more 

 arborescent, the alae wearing away up to the last segment. The illus- 

 tration on plate 3 is of the former state, and that on plate 2 is from 

 an exposed situation at Fort Ross, California, presumably the type 

 locality for the species. I have selected this specimen as the type 

 because it shows the proliferating habit Avhich seems to be the character 

 of the specimen illustrated by Agardh (see plate 1, figure 1). There 

 is considerable individual variation in the width of the segments. The 

 dimensions given in the diagnosis cover a very large majority of 

 individuals in a bed of plants, but occasionally wider or narrower 

 plants may be found. They fruit abundantly, only an occasional 

 segment remaining sterile to continue the growth and fruiting in the 

 next season if the plant persists. Most of the segments fruit simul- 

 taneously, and the height of the fruiting season is in June and July ; 

 some receptacles may, however, be found at any season of the year, as 

 is usually the case with all the species of the genus. 



The specimens after desiccation readily yield a copious amount of 

 mucilaginous substance on being revived, either with fresh or with salt 

 water. It was hoped that the copious secretion of mucilage might be 

 traced to the caecostomata which are so abundant in this species, and 

 that this definite function might be assigned to them, but it has not 

 been possible to connect these structures with this function. 



