Development of Laminaria hulbosa , L amour. 59 
and appear in ascending order in more or less regular series — in 
this respect resembling the adventitious roots of such a plant 
as Zea Mai's ; but in L. hulbosa the development of hapteres 
is restricted to one part of the stalk, and in fact to the bell 
developed below its junction with the lamina. This organ is 
not, however, to be regarded as the fused bases of many hap- 
teres, for it is a process of the stalk and differs markedly in 
histological characters from the hapteres. 
In this respect L. hulbosa differs very greatly from the other 
Laminarias ; and since the development of the hapteres is the 
character on which specific differences are based, there is per- 
haps a sufficient gap between our species and the rest to 
constitute it a separate genus. In looking through the 
synonyms of L. hulbosa one meets in fact with no less than 
three generic names. Decaisne seems to be responsible for 
two of these — Haligenia and Saccorhiza , the latter being 
founded on De la Pylaie’s suggestion. Kiitzing is responsible 
for PJiycocastanum. Unfortunately I have not had access to 
the descriptions of these authors. Agardh 1 has accepted De 
la Pylaie’s genus Saccorhiza , and finds the differences mainly in 
the character of the e root’ : the development of the sporangia 
upon the furbelows is also mentioned as a generic character. 
In other Laminarias the sporangia are confined to blisters 
on the flat lamina. In L. hulbosa they are developed on the 
bulb, on the furbelows and other parts of the stalk, and on the 
basal parts of the lamina. Differences in the position of re- 
productive organs are usually regarded as of great importance 
in distinguishing plants, and great stress was laid by the 
earlier writers on the presence of the sporangia on the furbelows. 
In the position of the normally placed sporangia this plant 
resembles Alaria esculenta. In the latter, special outgrowths 
from the stem, bearing the reproductive organs, appear at 
about the same point beneath the base of the lamina, as the 
ridge in L. hulbosa. These outgrowths are arranged in two 
rows, and appear in the same plane as the two wings of the 
1 Sp. Gen. et Ord. Alg. 1848. 
