116 Rhodora [JUNE 
interest him. Since the latter date, however, he has been unable to 
study the species in the field and it has seemed best to place before 
those who may have this opportunity, the results of this work, although 
incomplete, in the form of notes and suggestions. The papers of 
Farlow (1881) and Foslie (1884) will serve as a basis for the discus- 
sion of the New England forms, while frequent reference will be made 
to the articles of Guignard (1892) and various statements of Kjellman 
with regard to this group. 
The species of the genus Laminaria are first divided into two 
groups by most writers, according to the character of the blade. In 
one section, the Dzgřtatæe, the blade is more or less broad and split 
longitudinally into segments ; while in the other section, the Simp/ices, 
the blade is proportionally narrow, and normally entire. "These charac- 
ters are usually very marked and there is little difficulty in the case of 
a perfect specimen, in deciding to which of these sections it belongs. 
Occasionally, a digitate form persists to the time of fruiting, with an 
undivided blade; but in such a case, the section is made clear by the 
breadth and shape of the blade. In other cases, the simple forms 
may be split longitudinally, but this does not obscure the rela- 
tionship, since the specimen, if otherwise at all perfect, shows by 
the proportions of the blade, that it does not belong to the digitate 
section. 
Within each of the two main groups, the species are divided under 
sub-groups, according to the presence or absence of mucilage ducts 
in stipe or blade, or both. While there are certain conflicting state- 
ments in regard to the constancy of these latter characters in certain 
given species, it seems probable that these arise from the imperfect 
character of the investigations hitherto made, and that when all the 
various species have been thoroughly and carefully investigated, these 
contradictory statements will disappear. More study of the fresh 
material is needed for this, and students of this genus on the coasts of 
New England may, by careful attention to this matter, help greatly. 
Certain species have mucilage ducts in the stipe and certain others do 
not, the same being true for the blade. The subgroups, then, are as 
follows: 1. Mucilage ducts present in both stipe and blade; 2. Muci- 
lage ducts present in the blade but not in the stipe; 3. Mucilage 
ducts absent from both stipe and blade. The paper of Guignard 
(1892) should be consulted for details concerning the structure and 
course of the mucilage ducts, as well as for a resumé of the distribu- 
