ee 
me SOBSERVATIONS ON. PELVETIA. 
Moles HOLTZ. 
Pelvetia fastigrata (J. Ag.) DeToni, is a marine alga found 
distributed along the western coast of the United States and 
British Columbia. It grows in beds, attached to the rocks, be- 
tween high'and mid tide, and is, therefore, daily exposed to the 
feator several hours (77. V///.). The material studied for 
this paper was collected by Miss Josephine E. Tilden on Van- 
couver Island, in June, August, and December, 1901, and was 
preserved in formahn. 
There was originally some doubt in the minds of systematists 
whether this plant was a Pelvetza. It has been called Fucus 
fastigiatum (J. Agardh, Symb., I., 3) and Fucodium fastr- 
giatum (J. Agardh, Sp., I., 203). The difficulty of placing 
it arose from the uncertainty as to the number of eggs it forms 
in the odgone, and this point was left undecided by DeToni. 
Dr. W. A. Setchell seems to have been the first to demonstrate 
the true generic position.” | 
FEixternal appearance.—Felveiza is one of the smaller wracks. 
It is 10-20 cm. in height, and springs from a disc-shaped hold- 
fast with dichotomous branches repeated till it presents a fasci- 
cled appearance. In well-developed plants the stipe branches 
immediately above the holdfast, and the branches subdivide 
again but a short distance farther on, so that at first sight there 
seems to be several fronds arising from the same holdfast. The 
regular dichotomy near the base may be further confused by 
adventitious shoots springing from near the base of the main 
stipe. Inthe material at hand but one main stipe was observed 
arising from a holdfast. The front may undergo dichotomy a 
dozen times before the terminal laminz are reached. ‘The inter- 
nodes are longer toward the top. The codrdinate branches 
keep about equal growth, though a few may remain smaller and 
hence appear like lateral branches (P/. V/7/.). 
-*Setchell, W. A. Phyc. Bor. Am., No. 176. 
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