XXVI. OBSERVATIONS ON LAMINARIA BULLATA 



KJELLM. 



OLGA MUELLER. 



The plant, Laminar ia bullata, was first studied by Kjellman 

 in 1889 from material found by him in St. Lawrence Bay of St. 

 Lawrence island in Behring Sea. Some of the material used 

 for these observations was found by Miss Josephine Tilden at 

 Tracyton, Washington, but the greater part was collected 

 by the writer near Port Renfrew, on Vancouver island, on the 

 straits of Juan de Fuca, in August, 1902. From this it appears 

 that the plant has a wide distribution on the western coast of 

 North America, extending from Alaska to Puget sound, and 

 possibly to California. 



The writer is deeply indebted to Professor Conw r ay MacMillan 

 and to Miss Josephine Tilden for helpful suggestions. 



The plants collected at Port Renfrew were found growing 

 attached to rocks in a narrow arm of the sea leading into a 

 cave. Here the tidal currents were very strong, moving the 

 plants constantly to and fro, and bringing to them the food and 

 oxygen necessary for their life. They were found growing in 

 the sublittoral zone and could be collected only at low tide and 

 then with difficulty. 



EXTERNAL MORPHOLOGY. 



The plant, like other members of the Laminariaceae, consists 

 of three portions ; the holdfast, the stipe, and the lamina. The 

 distinguishing feature of the plant is its rows of undulations, 

 or of alternating elevations and depressions, called bullations, 

 which run nearly parallel to the margin of the lamina, but at 

 some distance from it. The color of the plant is dark brown. 

 The margin of the lamina is straight and not undulated. Its tex- 

 ture is like that of strong, firm, sheet rubber, and its smooth glisten- 

 ing surface offers but little resistance to the action of the waves. 



Plants of various ages were examined. The youngest was a 

 tiny individual 2.5 cm. in length. The primitive disc showed 

 to good advantage ; its lower surface was almost flat, while the 

 margin was slightly irregular, with indications of where the first 

 hapteric branches would arise. 



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