58 
Barber. — On the Structure and 
function is absorptive, represent the bunches of filaments projecting from the pits of 
other species. 
The development of the sporangia appears to take place in 
exactly the same manner as that of the rhizoids (Fig. 22). 
Epidermal cells become elongated, and a basal part is cut off 
from each: the distal end becomes either one of the paraphyses 
or a unilocular sporangium. This occurs all over the bulb on 
the inside as well as the outside. 
Differences from other Laminarias. 
The differences between Laminaria hdbosa and allied species 
are seen as well in the formation of the bulb and stalk as in 
the position of the sporangia. As has been already mentioned, 
L. btdbosavtdis not separated from L. digitata for a longtime — 
this being probably due to the similar character of the thick 
lamina. There are, as will be seen, numerous peculiarities 
in L. bidbosa marking it off very sharply from every other 
plant. 
Foslie, in a paper on the Laminarias of Norway 1 , divides 
them into three classes according to the development of the 
hapteres. L. bidbosa is not included in the list, presumably 
because it is to be placed in a separate genus. In the first 
type, Z. hyperborea^ — L . Cloustoni of text-books, Cuvy of Clou- 
ston), ‘ the hapteres are strong ; they are arranged in regular 
or nearly regular vertical series, and the primary haustorium is 
early loosened from the substratum.’ Z. digitata ( — L.Jiexi - 
caidis of Le Jolis, Tangle of Clouston) is put forward as a 
second type with ‘ hapteres in more or less horizontal, less re- 
gularly alternating whorls: the haustorium frequently retains 
its position till the end of the plant’s life.’ The third type in- 
cludes those in which the ‘hapteres are usually thin, much 
branched, long and pointed, almost always irregular in distri- 
bution.’ 
In all other Laminarias then, the hapteres arise as emergences, 
Ref. in Bot. Centralblatt, xxii. 193. 
