60 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
nucleus is now described in detail. For the term “ooblastema fila- 
ment” lie proposes to substitute “ sporogenous filaments.” 
In Dudresnaya purpurifera , when the protoplasm of the sporogenous 
cell fuses with that of the auxiliary cell, no fusion of the two nuclei 
takes place ; on the contrary, the nucleus of the auxiliary cell travels 
away from the sporogenous nucleus to the most distant part of its cell. 
After a time the sporogenous nucleus moves towards the sporogenous 
half of the cell, where the sporogenous filament is formed which makes 
its way between the vegetative branches of the thallus. When the 
sporogenous filament unites with the terminal cell of a lateral branch, 
there is again no fusion of the nuclei ; they remain far apart, the auxiliary 
nucleus gradually decreasing in size. 
The same general results were obtained in the other species examined. 
Jn Glceosiphonia ccipillaris, after the fusion of the sporogenous filament 
and the auxiliary cell, the auxiliary nucleus divides into two, and these 
two sister nuclei move towards the centre of the fused cell, close to the 
sporogenous nucleus. In Callithamnion corymbosum and Dasyci clegans 
also, the nucleus of the auxiliary cell and the sporogenous nucleus 
remain near each other without fusing. 
Without maintaining any true alternation of generations in the 
Floridem, Oltmanns distinguishes between the gametophyte or the 
structure which bears the sexual organs, and the sporophyte which bears 
the spores. The tetraspores are regarded as secondary organs of pro- 
pagation comparable to gemmae. In the simplest cases the sporophyte 
forms the simple glomerule ; but it is frequently represented by fila- 
ments growing among the cells and branches of the gametophyte, which 
enter into a characteristic union with special cells, the auxiliary cells ; 
but there is here no true fertilisation ; rather a process of the nature of 
a parasitism of the sporogenous on the auxiliary cell. 
Prof. Oltmanns frames a scheme of phylogenetic development of the 
Floridese, rising from Nemalion , through three lines of ascent, to the 
llhodomeleae, Corallina , and Champia. 
Structure and Development of Soranthera.* — Miss Ethel S. Barton 
has studied the life-history of this genus of Phaeophycese, of which the 
only known species, S. ulvoidea , is truly parasitic on Bliodomela Larix , 
being attached to it by rhizoids which penetrate the host-plant. The 
young plant consists of filaments radiating from the base, the cells at 
the surface bearing free assimilative filaments, like those of Chordaria. 
With the growth of the plant the internal structure is stretched and 
torn apart, leaving the centre empty. The assimilative filaments are 
shed, and the cells which bear them connect up to form a peripheral 
layer. Outgrowths which resemble plurilocular sporanges are asso- 
ciated with the assimilative filaments ; and unilocular sporanges, together 
with paraphyses, surround cryptostomates in the later stages of the 
plant. The systematic position of SorantTiera is at present doubtful ; 
it presents resemblances both to the Chordariacese and to the Encceliaceas. 
Phseoschizochlamys, a new Genus of Phaeophycese.t — Under the 
name Phseoschizochlamys mucosa g. et sp. n., Herr E. Lemmermann de- 
* Journ. Linn. Soc. (Bot.),xxxiii. (1898) pp. 479-82 (2 pis.). 
t Abhandl. Natur-ver. Bremen, xiv. (1898) pp. 501-12 (1 ph). See Hedwigia, 
xxxvii. (1898) Rep., p. 158. 
