316 Puget Sound Marine Sta. Pub. Vol, 1, No. 27 



common for kelp to endure through the winter.^*' It seems to be a ques- 

 tion of the ability of the plant to endure the rigorous environmental con- 

 ditions. The general vigor and tone of the individual plant must, of course, 

 be a large factor in this. The writer has seen no evidence that any speci- 

 mens last through the second winter. 



There does not seem to be any evidence of any resumption of growth 

 with the coming of the second season that would warrant the use of either 

 the term "biennial" or "perennial" with reference to these kelps. Their 

 life activities seem to be comprised in one cycle, but this may be pro- 

 iongd considerably by favorable environment. It is possible that internal 

 factors may also contribute to the longer life of some individuals and the 

 shorter life of others. How much of the duration of individuals of this 

 species may be due to the potentialities of the plant itiself and how much 

 to the influence of environmental conditions does not seem to have been 

 determined. 



The facts observed seem to be consistent with the idea that these kelps 

 fruit during practically the entire year, but that, at least in the Puget 

 Sound region, the fruiting is relatively so abundant during middle and 

 late summer as to justify calling this the normal fruiting season. If any 

 legal restriction is to be placed on the cutting of kelp in the interests 

 of conservation, it would seem that a portion of each bed should be left 

 uncut throughout the year rather than to limit all cutting to a definite 

 season. 



The mortality among young kelps is heavy. Many of the spores 

 germinate on places where the plants cannot continue to thrive. The fact 

 that many of them germinate on substrata which will not hold the plants^ ^ 

 when buoyancy of bulb and straining because of water movements begin 

 to test the quality of the attachment is evidenced by the large number of 

 T^oung kelps seen floating in early spring. 



The data given for the bed at Lincoln Beach indicate that many 

 spores germinate so far above low tide that the resulting kelps do not 

 •survive. The following causes may contribute to the deaLh of these indi- 

 viduals: (a) Desiccation during exposure at low tide, (b) Exposure to 

 strong light during this exposure, (c) Beating of the plants upon the 

 rocks due to tidal and wind movements of the water, (d) Grinding of 

 the young plants to death due to the shifting of small stones upon which 

 they have found attachment. 



Some evidence of the operation of (a) was seen during the summer 

 of 1916 at Lincoln Beach. This season was about three weeks later, how- 



loFrve, T. C. The kelp beds of souhteast Alaska. Rept. No. 100. U. S. 

 Dept. Agric, p. 66. 191.5. 



11 Cf. Frve, T. C. The kelp beds of southeast Alaska. Rept. No. 100. U. S. 

 Dept. Asric, p. 66. 1917. 



