290 
THALLOPHFTES. 
The Antheridia are either single cells at the end of long articulated branches, when, 
as in Batrachospermum, each produces only one antherozoid, or the mother-cells of the 
antherozoids are congregated together in large numbers on a common axis as the 
terminal members of a very short branching-system (as in Ceramiaceae). In Nitophyllum 
they densely cover certain portions of the surface of the thallus w^hich consists of a single 
layer of cells ; in the Melobesiaceae they are produced in cavities which are formed by 
the overarching of the surrounding tissue. The roundish antherozoids have no cilia and 
do not swarm, but are moved along passively by the water ; some of them are thus 
brought into contact with the trichogyne ; they adhere to it, and, in consequence of 
the absorption of the cell-walls at the points of contact, their contents pass into it. 
The trichogyne remains otherwise permanently closed. 
According to the structure of the Carpogonium, three types may be distinguished : 
(i) In the Nemalieae, to which Batrachospermum belongs^, the entire female organ 
consists, as in the Goleochaeteae, of a single cell, which is prolonged upwards into a 
Fig. \'i^.—Neu>alion multißdum ; / a branch with carpog-onium c and antherozoids sß ; II, 
III commencement of the formation of the sporocarp ; IV, V development of the chister of 
carpospores ; t the trichogyne ; c the carpogonium or sporocarp (after Thuret and Bornet). 
trichogyne (Fig. i88, 7, i). After fertilisation the basal portion of the carpogonium 
becomes multicellular in consequence of divisions having taken place (Fig. i88, //, c). 
The cells thus formed bulge outwards and give rise to a dense aggregation of short 
branches (7F, V, c), the terminal segments of which are the carpospores. This simple 
sporocarp acquires in Batrachospermum a loose investment by the outgrowth of pro- 
longations from the cells beneath the carpogonium. 
(2) In the Geramieae, Spermothamniese, Wrangelieae, &c., the carpogonium is a 
multicellular structure before fertilisation, which has arisen from the terminal cell of 
a short branch. A lateral row of the cells bears the trichogyne, and is termed the tri- 
chophore (Fig. iSg,jl,f). This structure undergoes no further developement after the 
carpogonium has been fertilised. Certain other cells, however, lying in the neighbour- 
^ As to Lemanea, which probably belongs to this group, see Sirodot, Ann, des Sei. Nat. 
5«^ Serie, vol. XVI. 1872. [Sirodot (Compt. Rend., 1873 and 1880) has found that the spores of 
Batrachospermum produce a Chantransia from which again the Batrachospermum is developed.] 
