22 Puget Sonr.d Marine Sta. Pub. Vol. 1, No. i 



case did the plant recover after the mucilage in the fruiting tips was 

 thoroughly dry. Although the table shows that Fucus can resist 48 

 hours of desiccation, in reality it was dry only about one half that time 

 even though it was out of water all of that time. About one half of 

 this time was during the night hours, when the plant often absorbs 

 moisture from the air instead of evaporating. This was shown by its 

 losing brittleness and becoming rubber-like in the late afternoon or evening. 



Gloiopeltis furcata seemed to be able to withstand considerable 

 desiccation. When dried it was at first rubber-like ; later it became 

 shriveled up, hard, and black. When it was returned to the water after 

 48 hours of exposure it regained its original color and a week's observa- 

 titon showed that the plant was still growing. 



Gigartina mamillosa varied considerable in its ability to withstand 

 desiccation. In some cases it became hard, brown and rubber-like; in 

 other cases the specimen became very hard and dry. Some of the 

 specimens turned white completely while others of the same exposure 

 turned white only at the tips and then gradually decayed when they were 

 returned to the water. 



Porphyra perforata is hard to handle because when it is dry it is 

 like a piece of shiny rubber stretched over the rocks and breaks very 

 easily. The plant was spread out on a rock under water, then exposed 

 and returned to the water with the rock. The older plants seemed to 

 die first in patches and around the edges, later the whole plant died. 



Halosaccion glandiforme dried out easily but the length of time re- 

 quired depended somewhat upon the size of the sac-like thallus and the 

 amount of water in it. These conditions caused the period of desiccation 

 which the plant could resist to vary from two to six hours. 



Colpomenia sinuosa could withstand from two to five hours of 

 desiccation depending upon the size of the plant and the amount of 

 water in the hollow mass of which the plant is composed. 



Rhodomela larix varied from two to four hours in the length of time 

 it could resist drying. The variations were probably due to the weather 

 variations from day to day and the differences in the size of the plant. 



Iridaea laminarioides can resist about four hours of drying. When 

 it is dry it is black and hard. When it is exposed for desiccation for 

 more than four hours it turns white when returned to the water. 



Ulva lactuca is a very difficult species to work with on account of its 

 size and the ease with which it breaks when it is dry. When the plant 



