i9o8] SETCHELL—NEREOCYSTIS AND PELACOFHYCUS 127 



splittings, thus taking place when the bulb is rapidly expanding, 

 become widely separated and form four to six centers for further split- 

 ting and growth. This is well shown in the fine plates of Postels 

 and RupRECHT (111. Alg. pis, 8, 9. 1840), in that of Saunders (.\lgae 

 of the Harriman Expedition, ph. 58, fig. i, and jp, fig. 8. 1898), 

 and less accurately in that of ]Mac:Milian (Bull. Torr. Bot. Club 

 26:pL 361. fig, 5. 1899). The normal certainly seems to be four 

 centers thus separated and which then proceed to form blades by 

 further splittings, but without any considerable separation. I have 

 also described this process in my paper *'Thc elk-kelp" (Erythea 

 4: 183. 1896). The type of division in this case is a regular dichotomy 

 but, as happens just as considerably in Lessonia, the absolute regu- 

 larity is interrupted in minor details. However, Nereocysiis Ludkcana 

 has the regularity of its dichotomy as complete as do the species of 

 Lessonia, and has no such scorpioid unilaterality in its branching and 

 in the succession of divisions leading up to it as does its near relative 

 Macrocystis. Between the two, but nearer, as it seems to me, to 

 Macrocystis in this respect is Pelagophycus. Skottsberg (Zur 

 Kenntn. d. Subantarkt. u. Antarkt. Meeresalgen 1:137, 138. 1907) 

 seems to take the opposite view and to consider that after the first 

 splitting in Nereocystis Lueikeam, the other splittings are unequal 

 as in Macrocystis. An investigation of a large number of older and 

 younger individuals convinces me that such is not the case. In 

 Postelsia also the splitting is largely equal, but finally there comes 

 something of unflateral splitting, so that while Postelsia reaHy stands 

 next to Lessonia and Nereocystis, it approaches slightly ako Pela- 

 gophycus. This point will be returned to below. 



Since the time of Mertens, it has been generaUy received and aU 

 e^adence has seemed to show that Nereocysiis Luetkeam, in spite of 

 its large size, is an annual plant. In his paper Frye has distmctly 

 discredited that belief, and whne he does not say so in so many words, 

 he intimates very strongly that it is a biennial plant. He says (/. c, 143) : 

 "Fishermen and pHots .... say that it disappears in winter," and 

 later (p. 143) he says: "The fishermen are partly n^t. Except 



, ___ 1 ^ *.u^^^ fT.^ I'^lr^ nrp crnnp: while those remaining 



away. 



.../Iv aU decayed and loose, with their fronds mmuy ton 

 " liiis observation was made in ^lardi to supplement obser 



