416 SUMMARY OF CURRENT RESEARCHES RELATING TO 
axis of the archegone ; the second is at right angles to the first. The 
prothallium is very long-lived, apparently living as much as six years. 
Formation of the Karyokinetic Spindle in Equisetum.* — Herr 
W. J. V. Osterhout gives the following as the main results of observa- 
tions in the first nuclear division in the spore-mother-cells of Equisetum 
limosum. At the time when the chromosomes separate, there is formed 
in the cytoplasm, close to the nuclear wall, a layer composed of fibres 
which at first run irregularly, but at length place themselves at right 
angles to the wall. Tufts of filaments are produced by the union of 
the polar ends. After the wall of the nucleus has disappeared, these 
filaments reach the nuclear cavity and combine with the fibres of the 
linin-framework. New groups are formed by fusion of the original 
groups, and then separate into two opposite divisions. Each division 
consists of several such groups, which finally fuse together and form a 
bipolar spindle. There appears to be a complete absence of centro- 
somes in this mode of formation of the spindle. 
Characeee. 
Division of the Nucleus in Chara.j — Herr B. Debski has investi- 
gated the mode of nuclear division in the vegetative cells and antheridial 
filaments of Chara fragilis. His conclusions differ materially from those 
of Johow, who was, he believes, led into error by mistaking the substance 
of the nucleoles for chromatin. The main results are as follows : — 
No distinct centrosomes could be detected in the process of division 
of the nucleus. Nucleole-like bodies are formed in the protoplasm, 
probably composed of nucleolar substance, and which show remarkable 
relationships to the spindle-fibres and the formation of the cell-plate. 
No reduction in the number of chromosomes takes place in the antherids. 
The process of karyokinesis exhibits much greater resemblance to that in 
the higher plants than to that in Algae. In Chara , as in the Archegoniata, 
the nuclear membrane is absorbed; while in most Algae karyokinesis 
takes place within the nuclear membrane, which is absorbed only at a 
later period. In Chara the formation of the cell-plate takes place centri- 
fugally. 
Shoot-Nodes of Characeae.J — Hr. K. Giesenhagen describes in detail 
the structure and mode of formation of the nodes in the aerial stems of 
the Characeae, especiallyfin Nitella gracilis and N. sy near pa. While the 
earlier stages in their formation show a remarkable uniformity through- 
out the family, a variety of differences are exhibited in the later stages, 
according to the species. 
Muscineee. 
Levierella, a new Genus of Musci. — Dr. C. Muller § defines as 
follows a new genus of Fabroniaceae from the Himalayas: — Cespites 
latos depressos entodontoideos sistens; caulis vage ramosus tenuis, 
ramis brevibus secundifoliis robustioribus, anguste subcomplanatis, et 
junioribus multo tenerioribus sparsifoliosis, valde divisus; folia e basi 
* Jahrb. f. wiss. Bot. (Pfeffer u. Strasburger), xxx. (1897) pp. 159-68 (2 pis.). 
(For method see p. 445.) 
f Tom. cit., pp. 227-48. Cf. this Journal, 1882, p. 79. (For method see p. 445.) 
% Flora, lxxxiii. (1897) pp. 160-202 (1 pi. and 17 figs.). Cf. this Journal, ante, 
p. 147. § Bull. Soc. Bot. Ital., 1897, pp. 73-4. 
