346 The Botanical Gazette. (June, 
such sporeling plants and the consequent interlacing of the 
filaments belonging to each seems a very probable method of 
formation for a plant with the axial structure of Nemalion. 
It also seems probable that the increase in length of the fila- 
ments developed on any of the plants found on the barnacle 
shells which there form red spots (fig. 10), the subsequent di- 
vision into branchlets, and the interlacing of these filaments 
may give rise to an erect frond of Nemalion. The possible 
origin of Mesogloia from similar ‘‘spots” has already been 
mentioned. 
In conclusion I would compare or homologize the prostrate 
series of rounded cells developed from a spore of Nemalion 
forming a short filament or a flat expansion of cells with that 
series of prostrate cells formed from the Batrachospermum 
spore and called by Sirodot a prothallus or protonema, and 
described by him as such in ‘‘Les Batrachospermes.” The 
resemblance seems so exact as to admit of calling this stage 
in Nemalion also a protonema. From this there arises the 
branched sporeling already described. The chantransia stage 
of Batrachospermum is an erect plant, branching irregularly 
and bearing the sexual plant as abud. This sexual plant has 
an axis of single cells placed end to end, covered by the 
branches which grow up and down its surface. In Lemanea, 
the chantransia is a similar branching plant, bearing the sex- 
ual plant as a bud. The resemblance between this stage '? 
Lemanea and Batrachospermum and the branched sporelings 
described in this paper is so close as to admit of calling these 
branched sporelings the chantransia stage of Nemalion. 
It remains my pleasant privilege to thank Dr. W. A- Set- 
chell of the University of California for his suggestive direc- 
tion of the work done on Nemalion at the Marine Biological 
Laboratory, at Woods Hole, Mass., in 1893, for material col- 
lected by him in 1894, and for criticism during the develop- 
ment of these observations. 
Smith College, Northampton, Mass. 
EXPLANATION OF PLaTEs XXV anp XXVI. 
Plate XXV. 
Fig. 1. Carpospore of Vemalion multifidum. X 409. 
Fig. 2. Spore in early stage of amore three days old. * we 
Fig. 3. Sporeling in later stage of germination (protonema); tak 
days old. x 400. 4, empty spore case; 2, second cell of plant; ’ 
orless protuberance developing into third cell of the plant- 
