738 MINNESOTA BOTANICAL STUDIES. 
ined. Within the layer of idioblasts the cortical cells become 
smaller on each side of the pith plate. This latter is composed 
of anastomosing filaments with occasional trumpet-hyphe and 
does not differ particularly from the same tissue as displayed in 
the stipe. The cortex of the mid-lamina and of the pinne 
seems to show some fairly constant differences. In the pinne 
the cells are often uniformly larger and the layer of idioblasts 
is frequently almost continuous. 
The sorus.—I do not find anywhere in the literature of Plery- 
gophora an account of its fruiting area. The first fruiting ma- 
terial that reached me was collected near Port Renfrew by Miss 
Josephine E. Tilden during December, 1901. Shortly after- 
wards Professor Setchell kindly sent me some dried pinnz col- 
lected at Whidby Island, Washington, by Mr. N. L. Gardner, 
and said to display sori. My observations are made from the 
fresh material collected by Miss Tilden. The soral patches 
occur upon the lateral pinnz and not upon the mid-lamina. In 
this respect they remind one of the soral distribution of Alara; 
but while in A/arza the entire pinna, except a very small mar- 
ginal region, is soriferous, in Plerygophora the sori form some- 
what irregular patches upon both surfaces of the pinna and 
much of its area fails to develop them. In this respect Plery- 
gophora approaches more nearly to Lamznarza. 
The sori are composed of numerous elongated, saccate goni- 
dangia, each bearing from fifty to two hundred spherical go- 
nidia. The gonidangial surface is surmounted by the inter- 
mingled paraphyses, averaging half as long again as the 
gonidangia and their clavate distal ends capped with cuticular 
masses, suggesting those already described for Lessonza and 
indicating that in this plant, as in Lessonza, the cuticular layer 
does not separate in a plate, as described for Lamznaria by 
Thuret and as known to occur also in WVereocystzs, but divides 
into individual paraphysal calyptra. Some gonidangia meas- 
ured indicated an average length of 50 mic. and diameter of 
to mic. The gonidia are nearly 2 mic. in diameter and ina 
double-stained preparation, made for me by Mr. H. L. Lyon, 
take Delafield’s hematoxylin while the paraphyses and cutic- 
ular substance take the safranin. The gonidangia and para- 
physes stand upon a floor-layer such as is found in all Laminaria- 
ceous sori, and their development does not differ from that 
which has already been described for other genera. 
