Lcmaneaceae of the United States. 193 
rhizoid ti has, from a cell of the Ckantransia-i orm, developed 
a series of cells that are a very little longer in comparison. 
Upon the upper surface of several of the cells a 1 protrusions 
of the wall appear. These protrusions are the beginnings of 
the main axes of new members of the Chan transia-ioxxsx. 
Subgenus Lemanea. The confervoid prostrate form of the 
subgenus Lemanea multiplies by the branching of the fila- 
ments composing the weft, and also by the development of 
rhizoids from the basal cells of the Chantransia-ioxm as in the 
subgenus Sacheria , except that the rhizoids rarely produce 
cellular tissue, but branch in the same manner as the elements 
of the weft. The branches arise from the side of the end 
toward the direction of growth. See Figs. 23, 25, and 26. 
In Fig. 26 the rhizoid a has arisen high up on the branch of 
the Chantransia- form, but this took place because the Chan - 
transia- form was crowded in the tuft. 
In point of origin we might speak of a primary prostrate 
form and a secondary prostrate form, but in point of time 
there is no such division. The primary prostrate form would 
of course be that which is developed from the spores and 
increases by multiplication of its own elements ; the secondary 
prostrate form would then be that which is developed from 
the rhizoids that grow out from the base of the Chantransia- 
form. But the portion of the prostrate form which has 
survived the summer produces the first increase of its ele- 
ments at the same time that the first elements of the Chan - 
transia- form are developed as erect lateral shoots. The basal 
cells of this new Chantransia-ioxm soon produce new elements 
of the prostrate form. A little later the spores germinate 
and produce in point of origin primary elements, and so on. 
So that in point of time the primary and secondary elements 
are practically the same, as indeed we find them to be mor- 
phologically and functionally l . 
1 Bornemann, loc. cit., pp. 6, 13, speaks of a ‘ primares Haftgewebe ’ developed 
from the spore, and a ‘ secundares Haftgewebe ’ developed from the rhizoids of the 
sexual shoot. He evidently entirely overlooked the development of the prostrate 
form from the Chantransia- form, which plays so important a part in the extension 
O 
