207 
Lemaneaceae of the United States. 
short as to consist of only one cell beside the tie-cells which 
would unite them to the wall. In rare cases, should the pro- 
carp arise from a tie-cell, it (the tie-cell) should be considered 
the homologue of a redundant generative filament, as all tie- 
cells are. 
Ketel 1 erred slightly in stating: ‘ Bei der Untergattung 
Sacheria (Fig. 22) entsprosst der Carpogonast, dessen End- 
zelle das “ Carpogonium,” die weibliche Sexualzelle, darstellt, 
gewohnlich einer Verbindungszelle, selten einer Zelle einer 
wandstandigen Zellreihe . 5 
Bornemann 2 erroneously states that all the procarps in both 
subgenera arise from the cells of the medullary layer, and 
devotes several pages to an attempt to refute Sirodot’s 3 idea 
of the ‘ tubes lateraux.’ There are also other evidences of 
careless observation by Bornemann. In Fig. 21. Taf. ii, he 
represents the spiral filaments around the central axis as 
arising from both the upper and lower face of the ray-cell, 
and as running up and down ! He says 4 , ‘ Die Anheftungszel- 
len . . . aus ihnen entspringen dtinne Zellfaden, welche nach 
oben und unten die axile Zellreihe spiralig umlaufen und mit 
ihr einen “ axilen Strang ” bilden.’ 
IV. Fertilization and Development of the 
Carpospores. 
Fertilization. Fertilization takes place during contact of the 
spermatozoid with the point of the trichogyne. The secure 
passage of the non-motile spermatozoid to the trichogyne is 
provided for by the great numbers of spermatozoids, the tufts 
of sexual shoots in close contact, the action of the water 
providing movement of the individuals of a tuft, and the 
mucilaginous substance coating the sexual shoot. Probably 
contact is generally brought about by the antherid-zone of 
one individual resting against the procarp-zone of another. 
1 Anat. Untersuch. iiber Lemanea, p. 36, 1886. 
2 Beitr'age zur Kenntniss der Lemaneaceen, pp. 26-32, 1887. 
3 Ann. d. Sci. Nat. Bot. 5th ser. xvi, 1872. 
4 Loc. cit. p. 10. 
