728 MINNESOTA BOTANICAL STUDIES. 
of corresponding size. The young forms of Plerygophora 
californica show the characteristic shape and developmental 
sequence of the Laminariacee, resembling particularly young 
plants of Laminarva saccharina. 
Plant ‘‘ B.” This specimen was collected by Mr: K. Yendo 
and was kindly presented tome by him. Itis apparently of about 
the same age as Ruprecht’s youngest plant. The whole plant 
is 35 cm. in length, of which 10 cm. is holdfast and stipe, 
and 25 cm. lamina. The lamina is 8 cm. in breadth at its 
broadest part. The tip is eroded, as usual, and in this particu- 
lar specimen the margin is imperfect. The stipe is 8 mm. in 
diameter, 3 cm. below the base of the lamina, and 5 mm. in di- 
ameter just above the holdfast, where it is circular in cross-sec- 
tion. It is, however, elliptical in cross section near the base of 
the lamina, the stipe being flattened in the plane of the lamina. 
In this specimen the midrib is beginning to differentiate and is 
well-marked for a distance of 5 cm. above the base of the lam- 
ina and faintly marked for 10 cm farther towards the tip. 
Distally it quite disappears. Certain hapteric outgrowths are 
decidedly long and slender in this plant—much more developed 
than ordinarily. 
In plant ‘* B,” less than 1 cm. below the base of the lamina, 
are seen two small emergences, opposite each other on the sides 
of the stipe. These are the growing points destined to produce 
the first pair of pinne. 
Plant «*C.” This is a somewhat older individual in which 
twelve pinne have been developed. The whole plant is 45 cm. 
in length from the holdfast to the eroded tip of the central 
lamina. From the holdfast to the lowest pinna is 15 cm. In 
this plant the four lower pinne are of a deep chocolate brown 
color and very much eroded and perforated. They present 
some points of anatomical interest as will be indicated later. 
The upper pinne are olive brown in color and the four upper- 
most have perfect tips, characteristically rounded, giving to the 
whole young pinna a distinctly spatulate shape. In texture 
these young pinne in the fresh plant are quite unlike the sporo- 
phylls of A/arza with which they have been compared. To the 
touch they feel not unlike thin sheets of celluloid. The central 
lamina has a more leathery feel, like Lamznarza or Lessonia. 
In this plant the stipe is 8 mm. in diameter, midway between 
the holdfast and the pinne. In the region of pinne it is de- 
