Postelsia 267 
one specimen the sorus is divided by a sterile 
portion of the lamina into two, and in several 
others it is almost divided. 
In contrast with the other kelps found in 
the wash not a specimen of the variety out of 
about forty seen, had a holdfast. Nearly all 
were cut off below the blade sharply as though 
bitten off by some kelp eating fish. All the 
other kelps including even Lessioniopsis, which 
clings jso, Securely that it will support —a 
a man’s weight, and Dictyoneuron, which grows 
out so far in deep water that its habitat at 
Port Renfrew has never been discovered, are 
torn up “‘by the roots’? and washed in whole 
as often as in fragments. This absence of 
holdfasts is the more significant because of 
their weakness and the ease with which they 
would be torn loose. 
The striking difference in the length of the 
lamine in shallow water specimens and those 
washed up from inaccessible depths shows 
more plainly the nice adjustment of strength 
of tissue and clinging power than any other 
kelp of the locality. Where wave action is 
