20 Puget Sound Marine Sta. Pub. Vol. 1, No. 4 



ticularly true near the low tide line where a number of species seem to 

 be struggling for the same area. 



The method of procedure was to collect, desiccate, examine, and 

 return the specimens to the water to see whether death had occured. Only 

 good fresh specimens were taken from the water and used in the ex- 

 periment. All the smaller species whenever possible were collected 

 with their holdfasts attached to their rock substrata. A large hammer 

 was used to chip off these rocks. The larger forms such as Alaria and 

 Nereocystis were pulled loose with their holdfasts into a rowboat and 

 then taken to the shore. Each specimen was labeled with a cloth tag 

 with a number on it and was then ready to be exposed. 



Only bright sunshiny days were used to dry the algae. This was 

 done so as to reduce the variation in the time required to dry the plants 

 to the point where they would not recover when they are returned to their 

 natural habitat in the water. Care was taken to spread out the plants 

 flat so that the parts of the thallus did not overlap. The specimens were 

 exposed between 8 and 10 o'clock in the morning and were left for a 

 definite length of time varying with the different species and individuals. 

 One plant was never exposed alone, duplicates were always made when- 

 ever an exposure was made. The length of exposure to desiccation was 

 determined b}^ beginning with two extremes of exposure, and then grad- 

 ually increasing the length of the minimum exposure and decreasing the 

 Jength of the maximum exposure until the approximate limit of resistance 

 to desiccation had been determined. Those plants which grow in the 

 Eublittoral zone were exposed from one to twenty-four hours and those 

 of the littoral zone were exposed from one to ninety-six hours, the time 

 varying with different species and individuals. 



At the end of the period of desiccation the specimens were examined 

 and then returned to the water. Those attached to rocks were placed on 

 the bottom along the shore line where they could be easily found. The 

 larger forms and those without rocks attached to them, were tied to a 

 float made of a log which was tied to a rock sounded to the bottom of 

 the sea. These specimens were then observed for a period of one to 

 seven days, to determine whether tliey were able to live after a particular 

 period of desiccation or whether it resulted in the death of the individual. 

 The death of the algae was determined by their changes in color. The 

 brown algae turn green when they die, except that Fucus turns red ; the 

 red algae turn white after death ; the green algae turn white and rapidly 

 decompose after death when returned to the water. An accurate record 

 was kept of the time of the exposure, the condition of each individual after 



