Macrocystis 61 
adopt the view of Areschoug and others that there are at least two 
reasonably distinct species of Macrocystis on the western coast of 
South America. И intermediates occur, the fact isnot shown by 
Dr. Coker’s specimens.* There is, 15, the long plant (commonly 
6 meters or more) of rather deep water (5 meters or more), with 
separate or isolated holdfasts, broad thin blades, and commonly 
subglobose vesicles—the Fucus Humboldtii of Bonpland, which is 
probably only a form of M. pyrifera (L.) Ag.; and 2d, the short 
plant (2-3 m. long) that grows gregariously on surf-swept rocks 
at or just below the low-tide mark, with densely intertangled 
rhizomatous holdfasts, narrowly linear, usually subentire thick 
blades, and commonly elongate vesicles (mostly 117-4 times 
as long as broad).f The latter is doubtless the plant known to 
Areschoug | as Macrocystis angustifolia Bory, but the plant on 
which Bory based most of his description of “ Macrocystis angus- 
fifolius" and which he soon afterwards figured under the slightly 
modified specific name angustifrons came from Australia and ap- 
pears to differ little from the typical M. pyrifera except in its nar- 
rower blades. Тһе earliest distinctive name for the small, narrow- 
leaved shallow-water plant of the western coast of South America, in 
the specific category at least, appears to be Bory's “ Macrocystis 
integrifolius," which name is perhaps unfortunate, as the absence 
of marginal teeth is rather less constant and characteristic than 
the narrowness of the blades. 
In one of Dr. Coker's specimens, 09166 (PLATE 22), found 
floating and lacking the holdfast, though probably representing 
practically the whole plant, the plant is 2.2 m. long and the stipe 
is slightly compressed or subterete; the blades are entire-margined 
(except the fertile basal), are smooth, narrowly linear, 7-12 cm. 
n 
r. Coker himself, however, (in litt. x inclines to = opinion that the two forms 
represent “individual adaptations within th 
he medulla, as seen in a cross section т i stipe, is usually much more 
compressed in the narrow-bladed plant than in the broad-bladed, but this varies in 
different parts of the plant and seems to be a rather unstable charact 
+ In the Chilean plant figured by Postels and Ruprecht as M. oni l- 
lust. Alg. 3. pl. 5. 1840), many of the blades are represented as plicate 
while in Dr. Сокегз Peruvian plants, they are smooth and plane A «а 
the marginal teeth also, are represented as numerous and subulate or cilium-like, 
while in these Peruvian plants, they are, when present, short and usually very blunt 
or truncate. 
