iQoS] SETCHELL—NEREOCYSTIS AND PELAGOPHYCUS 129 



elusion is based^ at least so far as they are presented, that it is not 

 nccessar}^ to assume that the initial growth of 2 or 3"* mu?t have 

 taken place in the previous year, especially when it is clear that a 

 growth of 18"" can occur in two months and a half, viz., from the 

 middle of March to the first of June. There certainly seem to be no 

 theoretical impossibilities in the way of its having all taken place in 



the same year. 



Nercocystis Luctkeana is fairly abundant on that portion of the 

 coast of California lying to the north of Point Conception and I have 

 followed its growth with some care. ^ly conclusions are different 

 from those of Frye. Many plants arise in pools and in the deeper 

 tideways among the reefs, and some persist through to the fruiting 

 stage. Such plants are easy of obser\'ation and the results may be 

 checked by more limited observation of the plants of the deeper waters. 

 I find that they appear in February and March, for the most part, 

 and in places where none are to be seen in December or Januar}-, and 

 that they pass through their different stages of growth and fruiting by 

 November, and for the most part disappear in December or January 

 of the same year. The young plants with and without bulte are in 

 greatest abundance in March, although in some yeai^ they are present 

 early in February, and this occurs in the same locality year after year. 

 Belated specimens appear later, but as stragglers, the general rule 

 being as stated above. It has been possible, therefore, to follow the 

 same group of individuals through their life -hist or}^, and the result 

 shows that the period of active existence is about nine or ten months 

 and within the period of one year. Exceptional times of germination 

 may occur and I find some, but in such cases the plants are usually 

 tide-pool plants and do not develop beyond a certain sta^. Mac- 

 Mtllan mentions (/. c. 274) a set of sporelings of 0.5^°^ and 

 upward in size, in two feet of water in June, off San Juan Inland, 

 Washington. I have never found any young plants so late in the year, 

 but I have found adult fruiting plants as late as April and in prime 

 condition, but they are decidedly out of season, and the cases can be 

 paraUeled among annual flowering plants, so that they do not i^aUy 

 affect the general truth of the statement ^ to the annual character 



of these plants. 



The floating seaweeds of the group of the Hiaeophyceae have long 



